Shc-like phosphotyrosine-binding (PTB) domain; Shc is a substrate for receptor tyrosine kinases, which can interact with phosphoproteins at NPXY motifs. Shc contains an PTB domain followed by an SH2 domain. PTB domains have a common PH-like fold and are found in various eukaryotic signaling molecules. This domain was initially shown to binds peptides with a NPXY motif with differing requirements for phosphorylation of the tyrosine, although more recent studies have found that some types of PTB domains can bind to peptides lack tyrosine residues altogether. In contrast to SH2 domains, which recognize phosphotyrosine and adjacent carboxy-terminal residues, PTB-domain binding specificity is conferred by residues amino-terminal to the phosphotyrosine. PTB domains are classified into three groups: phosphotyrosine-dependent Shc-like, phosphotyrosine-dependent IRS-like, and phosphotyrosine-independent Dab-like PTB domains. This cd is part of the Shc-like subgroup.

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 2462512593  36 RGWLHPNDKVMGPGVSYLVRYMGCVEVLQSMRALDFNTRTQVTREAISLVCEAVPGAKGATRRRKpcSRPLSSILGRSNL 115
Cdd:cd01209     1 RGWLHPDQLGMGPGVSYPVRYVGCIEVLQSMRSLDFNTRTQVTREAINRVCEAVGGAKGAKRKRK--SKALSSILGKSNL 78

                          90       100       110       120       130       140       150       160
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 2462512593 116 KFAGMPITLTVSTSSLNLMAADCKQIIANHHMQSISFASGGDPDTAEYVAYVAKDPVNQRACHILECPEGLAQDVISTIG 195
Cdd:cd01209    79 QFAGMNISLTISTDGLNLVTPDTGQIIANHHMQSISFASGGDPDTYDYVAYVAKDPVNQRACHVLECGDGLAQDVIATIG 158

                         170
                  ....*....|..
gi 2462512593 196 QAFELRFKQYLR 207
Cdd:cd01209   159 QAFELRFKQYLK 170

Shc-like phosphotyrosine-binding (PTB) domain; Shc is a substrate for receptor tyrosine kinases, which can interact with phosphoproteins at NPXY motifs. Shc contains an PTB domain followed by an SH2 domain. PTB domains have a common PH-like fold and are found in various eukaryotic signaling molecules. This domain was initially shown to binds peptides with a NPXY motif with differing requirements for phosphorylation of the tyrosine, although more recent studies have found that some types of PTB domains can bind to peptides lack tyrosine residues altogether. In contrast to SH2 domains, which recognize phosphotyrosine and adjacent carboxy-terminal residues, PTB-domain binding specificity is conferred by residues amino-terminal to the phosphotyrosine. PTB domains are classified into three groups: phosphotyrosine-dependent Shc-like, phosphotyrosine-dependent IRS-like, and phosphotyrosine-independent Dab-like PTB domains. This cd is part of the Shc-like subgroup.

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 2462512593  36 RGWLHPNDKVMGPGVSYLVRYMGCVEVLQSMRALDFNTRTQVTREAISLVCEAVPGAKGATRRRKpcSRPLSSILGRSNL 115
Cdd:cd01209     1 RGWLHPDQLGMGPGVSYPVRYVGCIEVLQSMRSLDFNTRTQVTREAINRVCEAVGGAKGAKRKRK--SKALSSILGKSNL 78

                          90       100       110       120       130       140       150       160
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 2462512593 116 KFAGMPITLTVSTSSLNLMAADCKQIIANHHMQSISFASGGDPDTAEYVAYVAKDPVNQRACHILECPEGLAQDVISTIG 195
Cdd:cd01209    79 QFAGMNISLTISTDGLNLVTPDTGQIIANHHMQSISFASGGDPDTYDYVAYVAKDPVNQRACHVLECGDGLAQDVIATIG 158

                         170
                  ....*....|..
gi 2462512593 196 QAFELRFKQYLR 207
Cdd:cd01209   159 QAFELRFKQYLK 170

Src homology 2 (SH2) domain found in SH2 adaptor protein C (SHC); SHC is involved in a wide variety of pathways including regulating proliferation, angiogenesis, invasion and metastasis, and bone metabolism. An adapter protein, SHC has been implicated in Ras activation following the stimulation of a number of different receptors, including growth factors [insulin, epidermal growth factor (EGF), nerve growth factor, and platelet derived growth factor (PDGF)], cytokines [interleukins 2, 3, and 5], erythropoietin, and granulocyte/macrophage colony-stimulating factor, and antigens [T-cell and B-cell receptors]. SHC has been shown to bind to tyrosine-phosphorylated receptors, and receptor stimulation leads to tyrosine phosphorylation of SHC. Upon phosphorylation, SHC interacts with another adapter protein, Grb2, which binds to the Ras GTP/GDP exchange factor mSOS which leads to Ras activation. SHC is composed of an N-terminal domain that interacts with proteins containing phosphorylated tyrosines, a (glycine/proline)-rich collagen-homology domain that contains the phosphorylated binding site, and a C-terminal SH2 domain. SH2 has been shown to interact with the tyrosine-phosphorylated receptors of EGF and PDGF and with the tyrosine-phosphorylated C chain of the T-cell receptor, providing one of the mechanisms of T-cell-mediated Ras activation. In general SH2 domains are involved in signal transduction. They typically bind pTyr-containing ligands via two surface pockets, a pTyr and hydrophobic binding pocket, allowing proteins with SH2 domains to localize to tyrosine phosphorylated sites.

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 2462512593 371 AEQLRGEPWFHGKLSRREAEALLQLNGDFLVR--------------------------------TKDHRFESVSHLISYH 418
Cdd:cd09925     1 AEQLRGEPWYHGKMSRRDAESLLQTDGDFLVRestttpgqyvltgmqngqpkhlllvdpegvvrTKDRVFESISHLINYH 80

                          90       100
                  ....*....|....*....|....
gi 2462512593 419 MDNHLPIISAGSELCLQQPVERKL 442
Cdd:cd09925    81 VTNGLPIISEGSELHLRRPVRRPA 104

Src homology 2 domains; Src homology 2 domains bind phosphotyrosine-containing polypeptides via 2 surface pockets. Specificity is provided via interaction with residues that are distinct from the phosphotyrosine. Only a single occurrence of a SH2 domain has been found in S. cerevisiae.

                           10        20        30        40        50        60        70        80
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 2462512593  377 EPWFHGKLSRREAEALLQLN--GDFLVR----------------------------------TKDHRFESVSHLISYHMD 420
Cdd:smart00252   1 QPWYHGFISREEAEKLLKNEgdGDFLVRdsesspgdyvlsvrvkgkvkhyrirrnedgkfylEGGRKFPSLVELVEHYQK 80

                   ....
gi 2462512593  421 NHLP 424
Cdd:smart00252  81 NSLG 84

Shc-like phosphotyrosine-binding (PTB) domain; Shc is a substrate for receptor tyrosine kinases, which can interact with phosphoproteins at NPXY motifs. Shc contains an PTB domain followed by an SH2 domain. PTB domains have a common PH-like fold and are found in various eukaryotic signaling molecules. This domain was initially shown to binds peptides with a NPXY motif with differing requirements for phosphorylation of the tyrosine, although more recent studies have found that some types of PTB domains can bind to peptides lack tyrosine residues altogether. In contrast to SH2 domains, which recognize phosphotyrosine and adjacent carboxy-terminal residues, PTB-domain binding specificity is conferred by residues amino-terminal to the phosphotyrosine. PTB domains are classified into three groups: phosphotyrosine-dependent Shc-like, phosphotyrosine-dependent IRS-like, and phosphotyrosine-independent Dab-like PTB domains. This cd is part of the Shc-like subgroup.

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 2462512593  36 RGWLHPNDKVMGPGVSYLVRYMGCVEVLQSMRALDFNTRTQVTREAISLVCEAVPGAKGATRRRKpcSRPLSSILGRSNL 115
Cdd:cd01209     1 RGWLHPDQLGMGPGVSYPVRYVGCIEVLQSMRSLDFNTRTQVTREAINRVCEAVGGAKGAKRKRK--SKALSSILGKSNL 78

                          90       100       110       120       130       140       150       160
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 2462512593 116 KFAGMPITLTVSTSSLNLMAADCKQIIANHHMQSISFASGGDPDTAEYVAYVAKDPVNQRACHILECPEGLAQDVISTIG 195
Cdd:cd01209    79 QFAGMNISLTISTDGLNLVTPDTGQIIANHHMQSISFASGGDPDTYDYVAYVAKDPVNQRACHVLECGDGLAQDVIATIG 158

                         170
                  ....*....|..
gi 2462512593 196 QAFELRFKQYLR 207
Cdd:cd01209   159 QAFELRFKQYLK 170

Src homology 2 (SH2) domain found in SH2 adaptor protein C (SHC); SHC is involved in a wide variety of pathways including regulating proliferation, angiogenesis, invasion and metastasis, and bone metabolism. An adapter protein, SHC has been implicated in Ras activation following the stimulation of a number of different receptors, including growth factors [insulin, epidermal growth factor (EGF), nerve growth factor, and platelet derived growth factor (PDGF)], cytokines [interleukins 2, 3, and 5], erythropoietin, and granulocyte/macrophage colony-stimulating factor, and antigens [T-cell and B-cell receptors]. SHC has been shown to bind to tyrosine-phosphorylated receptors, and receptor stimulation leads to tyrosine phosphorylation of SHC. Upon phosphorylation, SHC interacts with another adapter protein, Grb2, which binds to the Ras GTP/GDP exchange factor mSOS which leads to Ras activation. SHC is composed of an N-terminal domain that interacts with proteins containing phosphorylated tyrosines, a (glycine/proline)-rich collagen-homology domain that contains the phosphorylated binding site, and a C-terminal SH2 domain. SH2 has been shown to interact with the tyrosine-phosphorylated receptors of EGF and PDGF and with the tyrosine-phosphorylated C chain of the T-cell receptor, providing one of the mechanisms of T-cell-mediated Ras activation. In general SH2 domains are involved in signal transduction. They typically bind pTyr-containing ligands via two surface pockets, a pTyr and hydrophobic binding pocket, allowing proteins with SH2 domains to localize to tyrosine phosphorylated sites.

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 2462512593 371 AEQLRGEPWFHGKLSRREAEALLQLNGDFLVR--------------------------------TKDHRFESVSHLISYH 418
Cdd:cd09925     1 AEQLRGEPWYHGKMSRRDAESLLQTDGDFLVRestttpgqyvltgmqngqpkhlllvdpegvvrTKDRVFESISHLINYH 80

                          90       100
                  ....*....|....*....|....
gi 2462512593 419 MDNHLPIISAGSELCLQQPVERKL 442
Cdd:cd09925    81 VTNGLPIISEGSELHLRRPVRRPA 104

Phosphotyrosine-binding (PTB) PH-like fold; PTB domains have a common PH-like fold and are found in various eukaryotic signaling molecules. This domain was initially shown to bind peptides with a NPXY motif with differing requirements for phosphorylation of the tyrosine, although more recent studies have found that some types of PTB domains can bind to peptides lack tyrosine residues altogether. In contrast to SH2 domains, which recognize phosphotyrosine and adjacent carboxy-terminal residues, PTB-domain binding specificity is conferred by residues amino-terminal to the phosphotyrosine. PTB domains are classified into three groups: phosphotyrosine-dependent Shc-like, phosphotyrosine-dependent IRS-like, and phosphotyrosine-independent Dab-like PTB domains.

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 2462512593  50 VSYLVRYMGCVEVLQSMRAldfntrtQVTREAISLVceavpgakgatrrrkpcsrplssILGRSNLKFAGMPITLTVSTS 129
Cdd:cd00934     1 ASFQVKYLGSVEVGSSRGV-------DVVEEALKAL-----------------------AAALKSSKRKPGPVLLEVSSK 50

                          90       100       110       120       130       140       150
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|.
gi 2462512593 130 SLNLMAADCKQIIANHHMQSISFaSGGDPDTAEYVAYVAKDP-VNQRACHILECP-EGLAQDVISTIGQAF 198
Cdd:cd00934    51 GVKLLDLDTKELLLRHPLHRISY-CGRDPDNPNVFAFIAGEEgGSGFRCHVFQCEdEEEAEEILQAIGQAF 120

Ankyrin repeat and sterile alpha motif (SAM) domain-containing (Anks) protein family Phosphotyrosine-binding (PTB) domain; Both AIDA-1b (AbetaPP intracellular domain-associated protein 1b) and Odin (also known as ankyrin repeat and sterile alpha motif domain-containing 1A; ANKS1A) belong to the Anks protein family. Both of these family members interacts with the EphA8 receptor. Ank members consists of ankyrin repeats, a SAM domain and a C-terminal PTB domain which is crucial for interaction with the juxtamembrane (JM) region of EphA8. PTB domains are classified into three groups, namely, phosphotyrosine-dependent Shc-like, phosphotyrosine-dependent IRS-like, and phosphotyrosine-independent Dab-like PTB domains of which the Anks PTB is a member. PTB domains have a common PH-like fold and are found in various eukaryotic signaling molecules. This domain was initially shown to binds peptides with a NPXY motif with differing requirements for phosphorylation of the tyrosine, although more recent studies have found that some types of PTB domains can bind to peptides lack tyrosine residues altogether. In contrast to SH2 domains, which recognize phosphotyrosine and adjacent carboxy-terminal residues, PTB-domain binding specificity is conferred by residues amino-terminal to the phosphotyrosine. PTB domains are classified into three groups: phosphotyrosine-dependent Shc-like, phosphotyrosine-dependent IRS-like, and phosphotyrosine-independent Dab-like PTB domains. This cd is part of the Dab-like subgroup.

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 2462512593  38 WLHPNDKVMGPGVSYLVRYMGCVEVLqsmraldfNTR-TQVTREAIslvceavpgAKGATRRRKPCSRPlssilgrsnlk 116
Cdd:cd01274     3 WRHSPEKLITGSVNYEAHYLGSTEIK--------ELRgTESTKKAI---------QKLKKSTREMKKIP----------- 54

                          90       100       110       120       130       140       150       160
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 2462512593 117 fagmPITLTVSTSSLNLMAADCKQIIANHHMQSISFASGgDPDTAEYVAYVAKDPVNQRA-CHILECPE-GLAQDVISTI 194
Cdd:cd01274    55 ----TIILSISYKGVKFIDATTKNLICEHEIRNISCACQ-DPEDLNTFAYITKDLKTDHHyCHVFCVLTvDLATEIILTL 129

                         170
                  ....*....|...
gi 2462512593 195 GQAFELRFKQYLR 207
Cdd:cd01274   130 GQAFEVAYQLALR 142

Src homology 2 (SH2) domain in the Breast Cancer Anti-estrogen Resistance protein 3; BCAR3 is part of a growing family of guanine nucleotide exchange factors is responsible for activation of Ras-family GTPases, including Sos1 and 2, GRF1 and 2, CalDAG-GEF/GRP1-4, C3G, cAMP-GEF/Epac 1 and 2, PDZ-GEFs, MR-GEF, RalGDS family members, RalGPS, RasGEF, Smg GDS, and phospholipase C(epsilon). 12102558 21262352 BCAR3 binds to the carboxy-terminus of BCAR1/p130Cas, a focal adhesion adapter protein. Over expression of BCAR1 (p130Cas) and BCAR3 induces estrogen independent growth in normally estrogen-dependent cell lines. They have been linked to resistance to anti-estrogens in breast cancer, Rac activation, and cell motility, though the BCAR3/p130Cas complex is not required for this activity in BCAR3. Many BCAR3-mediated signaling events in epithelial and mesenchymal cells are independent of p130Cas association. Structurally these proteins contain a single SH2 domain upstream of their RasGEF domain, which is responsible for the ability of BCAR3 to enhance p130Cas over-expression-induced migration. In general SH2 domains are involved in signal transduction. They typically bind pTyr-containing ligands via two surface pockets, a pTyr and hydrophobic binding pocket, allowing proteins with SH2 domains to localize to tyrosine phosphorylated sites.

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 2462512593 372 EQLRGEPWFHGKLSRREAEALLQLNGDFLVR------------------------TKDHR-----------------FES 410
Cdd:cd10337     1 EDLRSHAWYHGRIPRQVAESLVQREGDFLVRdslsspgdyvltcrwkgqplhfkiNRVVLrpseaytrvqyqfedeqFDS 80

                          90       100       110
                  ....*....|....*....|....*....|
gi 2462512593 411 VSHLISYHMDNHLPiISAGSELCLQQPVER 440
Cdd:cd10337    81 IPALVHFYVGNRRP-ISQASGAIISRPVNR 109

Tyrosine-specific kinase/HM-motif TK (TM/HMTK) Phosphotyrosine-binding (PTB) PH-like fold; TK kinases catalyzes the transfer of the terminal phosphate of ATP to a specific tyrosine residue on its target protein. TK kinases play significant roles in development and cell division. Tyrosine-protein kinases can be divided into two subfamilies: receptor tyrosine kinases, which have an intracellular tyrosine kinase domain, a transmembrane domain and an extracellular ligand-binding domain; and non-receptor (cytoplasmic) tyrosine kinases, which are soluble, cytoplasmic kinases. In HMTK the conserved His-Arg-Asp sequence within the catalytic loop is replaced by a His-Met sequence. TM/HMTK have are 2-3 N-terminal PTB domains. PTB domains in TKs are thought to function analogously to the membrane targeting (PH, myristoylation) and pTyr binding (SH2) domains of Src subgroup kinases. PTB domains have a common PH-like fold and are found in various eukaryotic signaling molecules. This domain was initially shown to binds peptides with a NPXY motif with differing requirements for phosphorylation of the tyrosine, although more recent studies have found that some types of PTB domains can bind to peptides lack tyrosine residues altogether. In contrast to SH2 domains, which recognize phosphotyrosine and adjacent carboxy-terminal residues, PTB-domain binding specificity is conferred by residues amino-terminal to the phosphotyrosine. PTB domains are classified into three groups: phosphotyrosine-dependent Shc-like, phosphotyrosine-dependent IRS-like, and phosphotyrosine-independent Dab-like PTB domains. This cd is part of the Dab-like subgroup.

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 2462512593 115 LKFAGMPITLTVSTSSLNLMAADCKQIIANHHMQSISFaSGGDPDTAEYVAYVAKDPVNQRA-CHILECPEGlAQDVIST 193
Cdd:cd13161    33 LKLKPKPVVLVVSSEGIRVVERLTGEVLTNVPIKDISF-VTVDPKDKKLFAFISHDPRLGRItCHVFRCKRG-AQEICDT 110

                  ....*.
gi 2462512593 194 IGQAFE 199
Cdd:cd13161   111 IAEAFK 116

Src homology 2 (SH2) domain; In general, SH2 domains are involved in signal transduction; they bind pTyr-containing polypeptide ligands via two surface pockets, a pTyr and hydrophobic binding pocket, allowing proteins with SH2 domains to localize to tyrosine phosphorylated sites. They are present in a wide array of proteins including: adaptor proteins (Nck1, Crk, Grb2), scaffolds (Slp76, Shc, Dapp1), kinases (Src, Syk, Fps, Tec), phosphatases (Shp-1, Shp-2), transcription factors (STAT1), Ras signaling molecules (Ras-Gap), ubiquitination factors (c-Cbl), cytoskeleton regulators (Tensin), signal regulators (SAP), and phospholipid second messengers (PLCgamma), amongst others.

                          10        20
                  ....*....|....*....|....*..
gi 2462512593 378 PWFHGKLSRREAEALLQLN--GDFLVR 402
Cdd:cd00173     1 PWFHGSISREEAERLLRGKpdGTFLVR 27

Src homology 2 (SH2) domain found in Abelson murine lymphosarcoma virus (ABL) proteins; ABL-family proteins are highly conserved tyrosine kinases. Each ABL protein contains an SH3-SH2-TK (Src homology 3-Src homology 2-tyrosine kinase) domain cassette, which confers autoregulated kinase activity and is common among nonreceptor tyrosine kinases. Several types of posttranslational modifications control ABL catalytic activity, subcellular localization, and stability, with consequences for both cytoplasmic and nuclear ABL functions. Binding partners provide additional regulation of ABL catalytic activity, substrate specificity, and downstream signaling. By combining this cassette with actin-binding and -bundling domain, ABL proteins are capable of connecting phosphoregulation with actin-filament reorganization. Vertebrate paralogs, ABL1 and ABL2, have evolved to perform specialized functions. ABL1 includes nuclear localization signals and a DNA binding domain which is used to mediate DNA damage-repair functions, while ABL2 has additional binding capacity for actin and for microtubules to enhance its cytoskeletal remodeling functions. SH2 is involved in several autoinhibitory mechanism that constrain the enzymatic activity of the ABL-family kinases. In one mechanism SH2 and SH3 cradle the kinase domain while a cap sequence stabilizes the inactive conformation resulting in a locked inactive state. Another involves phosphatidylinositol 4,5-bisphosphate (PIP2) which binds the SH2 domain through residues normally required for phosphotyrosine binding in the linker segment between the SH2 and kinase domains. The SH2 domain contributes to ABL catalytic activity and target site specificity. It is thought that the ABL catalytic site and SH2 pocket have coevolved to recognize the same sequences. Recent work now supports a hierarchical processivity model in which the substrate target site most compatible with ABL kinase domain preferences is phosphorylated with greatest efficiency. If this site is compatible with the ABL SH2 domain specificity, it will then reposition and dock in the SH2 pocket. This mechanism also explains how ABL kinases phosphorylates poor targets on the same substrate if they are properly positioned and how relatively poor substrate proteins might be recruited to ABL through a complex with strong substrates that can also dock with the SH2 pocket. In general SH2 domains are involved in signal transduction. They typically bind pTyr-containing ligands via two surface pockets, a pTyr and hydrophobic binding pocket, allowing proteins with SH2 domains to localize to tyrosine phosphorylated sites.

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 2462512593 377 EPWFHGKLSRREAEALLQ--LNGDFLVR----------------------------------TKDHRFESVSHLISYHMD 420
Cdd:cd09935     3 HSWYHGPISRNAAEYLLSsgINGSFLVResesspgqysislrydgrvyhyrisedsdgkvyvTQEHRFNTLAELVHHHSK 82

                  ..
gi 2462512593 421 NH 422
Cdd:cd09935    83 NA 84

Src homology 2 domain found in SH2 domain-containing adapter proteins B, D, E, and F (SHB, SHD, SHE, SHF); SHB, SHD, SHE, and SHF are SH2 domain-containing proteins that play various roles throughout the cell. SHB functions in generating signaling compounds in response to tyrosine kinase activation. SHB contains proline-rich motifs, a phosphotyrosine binding (PTB) domain, tyrosine phosphorylation sites, and a SH2 domain. SHB mediates certain aspects of platelet-derived growth factor (PDGF) receptor-, fibroblast growth factor (FGF) receptor-, neural growth factor (NGF) receptor TRKA-, T cell receptor-, interleukin-2 (IL-2) receptor- and focal adhesion kinase- (FAK) signaling. SRC-like FYN-Related Kinase FRK/RAK (also named BSK/IYK or GTK) and SHB regulate apoptosis, proliferation and differentiation. SHB promotes apoptosis and is also required for proper mitogenicity, spreading and tubular morphogenesis in endothelial cells. SHB also plays a role in preventing early cavitation of embryoid bodies and reduces differentiation to cells expressing albumin, amylase, insulin and glucagon. SHB is a multifunctional protein that has difference responses in different cells under various conditions. SHE is expressed in heart, lung, brain, and skeletal muscle, while expression of SHD is restricted to the brain. SHF is mainly expressed in skeletal muscle, brain, liver, prostate, testis, ovary, small intestine, and colon. SHD may be a physiological substrate of c-Abl and may function as an adapter protein in the central nervous system. It is also thought to be involved in apoptotic regulation. SHD contains five YXXP motifs, a substrate sequence preferred by Abl tyrosine kinases, in addition to a poly-proline rich region and a C-terminal SH2 domain. SHE contains two pTry protein binding domains, protein interaction domain (PID) and a SH2 domain, followed by a glycine-proline rich region, all of which are N-terminal to the phosphotyrosine binding (PTB) domain. SHF contains four putative tyrosine phosphorylation sites and an SH2 domain. In general SH2 domains are involved in signal transduction. They typically bind pTyr-containing ligands via two surface pockets, a pTyr and hydrophobic binding pocket, allowing proteins with SH2 domains to localize to tyrosine phosphorylated sites.

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 2462512593 377 EPWFHGKLSRREAEALLQL--NGDFLVR--------------------------TKDHR---------FESVSHLISYHM 419
Cdd:cd09945     1 QGWYHGAITRIEAESLLRPckEGSYLVRnsestkqdyslslksakgfmhmriqrNETGQyilgqfsrpFETIPEMIRHYC 80

                          90       100
                  ....*....|....*....|
gi 2462512593 420 DNHLPIisAGSE-LCLQQPV 438
Cdd:cd09945    81 LNKLPV--RGAEhMCLLEPV 98

N-terminal Src homology 2 (N-SH2) domain in Phospholipase C gamma; Phospholipase C gamma is a signaling molecule that is recruited to the C-terminal tail of the receptor upon autophosphorylation of a highly conserved tyrosine. PLCgamma is composed of a Pleckstrin homology (PH) domain followed by an elongation factor (EF) domain, 2 catalytic regions of PLC domains that flank 2 tandem SH2 domains (N-SH2, C-SH2), and ending with a SH3 domain and C2 domain. N-SH2 SH2 domain-mediated interactions represent a crucial step in transmembrane signaling by receptor tyrosine kinases. SH2 domains recognize phosphotyrosine (pY) in the context of particular sequence motifs in receptor phosphorylation sites. Both N-SH2 and C-SH2 have a very similar binding affinity to pY. But in growth factor stimulated cells these domains bind to different target proteins. N-SH2 binds to pY containing sites in the C-terminal tails of tyrosine kinases and other receptors. Recently it has been shown that this interaction is mediated by phosphorylation-independent interactions between a secondary binding site found exclusively on the N-SH2 domain and a region of the FGFR1 tyrosine kinase domain. This secondary site on the SH2 cooperates with the canonical pY site to regulate selectivity in mediating a specific cellular process. C-SH2 binds to an intramolecular site on PLCgamma itself which allows it to hydrolyze phosphatidylinositol-4,5-bisphosphate into diacylglycerol and inositol triphosphate. These then activate protein kinase C and release calcium. In general SH2 domains are involved in signal transduction. They typically bind pTyr-containing ligands via two surface pockets, a pTyr and hydrophobic binding pocket, allowing proteins with SH2 domains to localize to tyrosine phosphorylated sites.

                          10        20        30
                  ....*....|....*....|....*....|....
gi 2462512593 376 GEPWFHGKLS--RREAEALLQ-----LNGDFLVR 402
Cdd:cd10341     3 TEPWFHGKLGdgRDEAEKLLLeycegGDGTFLVR 36

Src homology 2 (SH2) domain found in the Src family of non-receptor tyrosine kinases; The Src family kinases are nonreceptor tyrosine kinases that have been implicated in pathways regulating proliferation, angiogenesis, invasion and metastasis, and bone metabolism. It is thought that transforming ability of Src is linked to its ability to activate key signaling molecules in these pathways, rather than through direct activity. As such blocking Src activation has been a target for drug companies. Src family members can be divided into 3 groups based on their expression pattern: 1) Src, Fyn, and Yes; 2) Blk, Fgr, Hck, Lck, and Lyn; and 3) Frk-related kinases Frk/Rak and Iyk/Bsk Of these, cellular c-Src is the best studied and most frequently implicated in oncogenesis. The c-Src contains five distinct regions: a unique N-terminal domain, an SH3 domain, an SH2 domain, a kinase domain and a regulatory tail, as do the other members of the family. Src exists in both active and inactive conformations. Negative regulation occurs through phosphorylation of Tyr, resulting in an intramolecular association between phosphorylated Tyr and the SH2 domain of SRC, which locks the protein in a closed conformation. Further stabilization of the inactive state occurs through interactions between the SH3 domain and a proline-rich stretch of residues within the kinase domain. Conversely, dephosphorylation of Tyr allows SRC to assume an open conformation. Full activity requires additional autophosphorylation of a Tyr residue within the catalytic domain. Loss of the negative-regulatory C-terminal segment has been shown to result in increased activity and transforming potential. Phosphorylation of the C-terminal Tyr residue by C-terminal Src kinase (Csk) and Csk homology kinase results in increased intramolecular interactions and consequent Src inactivation. Specific phosphatases, protein tyrosine phosphatase a (PTPa) and the SH-containing phosphatases SHP1/SHP2, have also been shown to take a part in Src activation. Src is also activated by direct binding of focal adhesion kinase (Fak) and Crk-associated substrate (Cas) to the SH2 domain. SRC activity can also be regulated by numerous receptor tyrosine kinases (RTKs), such as Her2, epidermal growth factor receptor (EGFR), fibroblast growth factor receptor, platelet-derived growth factor receptor (PDGFR), and vascular endothelial growth factor receptor (VEGFR). In general SH2 domains are involved in signal transduction. They typically bind pTyr-containing ligands via two surface pockets, a pTyr and hydrophobic binding pocket, allowing proteins with SH2 domains to localize to tyrosine phosphorylated sites.

                          10        20        30
                  ....*....|....*....|....*....|
gi 2462512593 377 EPWFHGKLSRREAEALLQL----NGDFLVR 402
Cdd:cd09933     3 EEWFFGKIKRKDAEKLLLApgnpRGTFLIR 32

Src homology 2 (SH2) domain found in SH2B adapter protein family; The SH2B adapter protein family has 3 members: SH2B1 (SH2-B, PSM), SH2B2 (APS), and SH2B3 (Lnk). SH2B family members contain a pleckstrin homology domain, at least one dimerization domain, and a C-terminal SH2 domain which binds to phosphorylated tyrosines in a variety of tyrosine kinases. SH2B1 and SH2B2 function in signaling pathways found downstream of growth hormone receptor and receptor tyrosine kinases, including the insulin, insulin-like growth factor-I (IGF-I), platelet-derived growth factor (PDGF), nerve growth factor, hepatocyte growth factor, and fibroblast growth factor receptors. SH2B2beta, a new isoform of SH2B2, is an endogenous inhibitor of SH2B1 and/or SH2B2 (SH2B2alpha), negatively regulating insulin signaling and/or JAK2-mediated cellular responses. SH2B3 negatively regulates lymphopoiesis and early hematopoiesis. The lnk-deficiency results in enhanced production of B cells, and expansion as well as enhanced function of hematopoietic stem cells (HSCs), demonstrating negative regulatory functions of Sh2b3/Lnk in cytokine signaling. Sh2b3/Lnk also functions in responses controlled by cell adhesion and in crosstalk between integrin- and cytokine-mediated signaling. In general SH2 domains are involved in signal transduction. They typically bind pTyr-containing ligands via two surface pockets, a pTyr and hydrophobic binding pocket, allowing proteins with SH2 domains to localize to tyrosine phosphorylated sites.

                          10        20        30
                  ....*....|....*....|....*....|....*....
gi 2462512593 374 LRGEPWFHGKLSRREAEALLQLNGD-----FLVRTKDHR 407
Cdd:cd10346     5 LSEYPWFHGTLSRSDAAQLVLHSGAdghgvFLVRQSETR 43

C-terminal Src homology 2 (C-SH2) domain in Phospholipase C gamma; Phospholipase C gamma is a signaling molecule that is recruited to the C-terminal tail of the receptor upon autophosphorylation of a highly conserved tyrosine. PLCgamma is composed of a Pleckstrin homology (PH) domain followed by an elongation factor (EF) domain, 2 catalytic regions of PLC domains that flank 2 tandem SH2 domains (N-SH2, C-SH2), and ending with a SH3 domain and C2 domain. N-SH2 SH2 domain-mediated interactions represent a crucial step in transmembrane signaling by receptor tyrosine kinases. SH2 domains recognize phosphotyrosine (pY) in the context of particular sequence motifs in receptor phosphorylation sites. Both N-SH2 and C-SH2 have a very similar binding affinity to pY. But in growth factor stimulated cells these domains bind to different target proteins. N-SH2 binds to pY containing sites in the C-terminal tails of tyrosine kinases and other receptors. Recently it has been shown that this interaction is mediated by phosphorylation-independent interactions between a secondary binding site found exclusively on the N-SH2 domain and a region of the FGFR1 tyrosine kinase domain. This secondary site on the SH2 cooperates with the canonical pY site to regulate selectivity in mediating a specific cellular process. C-SH2 binds to an intramolecular site on PLCgamma itself which allows it to hydrolyze phosphatidylinositol-4,5-bisphosphate into diacylglycerol and inositol triphosphate. These then activate protein kinase C and release calcium. In general SH2 domains are involved in signal transduction. They typically bind pTyr-containing ligands via two surface pockets, a pTyr and hydrophobic binding pocket, allowing proteins with SH2 domains to localize to tyrosine phosphorylated sites.

                          10        20        30
                  ....*....|....*....|....*....|...
gi 2462512593 376 GEPWFHGKLSRREAEALL---QLNGDFLVRTKD 405
Cdd:cd09932     3 SKEWFHANLTREQAEEMLmrvPRDGAFLVRPSE 35

Src homology 2 domain found in Growth factor receptor-bound protein 2 (Grb2) and similar proteins; The adaptor proteins here include homologs Grb2 in humans, Sex muscle abnormal protein 5 (Sem-5) in Caenorhabditis elegans, and Downstream of receptor kinase (drk) in Drosophila melanogaster. They are composed of one SH2 and two SH3 domains. Grb2/Sem-5/drk regulates the Ras pathway by linking the tyrosine kinases to the Ras guanine nucleotide releasing protein Sos, which converts Ras to the active GTP-bound state. The SH2 domain of Grb2/Sem-5/drk binds class II phosphotyrosyl peptides while its SH3 domain binds to Sos and Sos-derived, proline-rich peptides. Besides it function in Ras signaling, Grb2 is also thought to play a role in apoptosis. Unlike most SH2 structures in which the peptide binds in an extended conformation (such that the +3 peptide residue occupies a hydrophobic pocket in the protein, conferring a modest degree of selectivity), Grb2 forms several hydrogen bonds via main chain atoms with the side chain of +2 Asn. In general SH2 domains are involved in signal transduction. They typically bind pTyr-containing ligands via two surface pockets, a pTyr and hydrophobic binding pocket, allowing proteins with SH2 domains to localize to tyrosine phosphorylated sites.

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                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 2462512593 378 PWFHGKLSRREAEALL---QLNGDFLVRT------------------------KDH---------RFESVSHLISYHMDN 421
Cdd:cd09941     4 PWFHGKISRAEAEEILmnqRPDGAFLIREsesspgdfslsvkfgndvqhfkvlRDGagkyflwvvKFNSLNELVDYHRTT 83

                  .
gi 2462512593 422 H 422
Cdd:cd09941    84 S 84

Src homology 2 domain found in SH2 domain-containing adapter proteins D (SHD); The expression of SHD is restricted to the brain. SHD may be a physiological substrate of c-Abl and may function as an adapter protein in the central nervous system. It is also thought to be involved in apoptotic regulation. SHD contains five YXXP motifs, a substrate sequence preferred by Abl tyrosine kinases, in addition to a poly-proline rich region and a C-terminal SH2 domain. In general SH2 domains are involved in signal transduction. They typically bind pTyr-containing ligands via two surface pockets, a pTyr and hydrophobic binding pocket, allowing proteins with SH2 domains to localize to tyrosine phosphorylated sites.

                          10        20        30
                  ....*....|....*....|....*....|....*...
gi 2462512593 377 EPWFHGKLSRREAEALLQL--NGDFLVRTKDHRFESVS 412
Cdd:cd10390     1 QPWFHGPLSRADAENLLSLckEGSYLVRLSETRPQDCS 38

C-terminal Src homology 2 (SH2) domain found in Ras GTPase-activating protein 1 (GAP); RasGAP is part of the GAP1 family of GTPase-activating proteins. The protein is located in the cytoplasm and stimulates the GTPase activity of normal RAS p21, but not its oncogenic counterpart. Acting as a suppressor of RAS function, the protein enhances the weak intrinsic GTPase activity of RAS proteins resulting in RAS inactivation, thereby allowing control of cellular proliferation and differentiation. Mutations leading to changes in the binding sites of either protein are associated with basal cell carcinomas. Alternative splicing results in two isoforms. The shorter isoform which lacks the N-terminal hydrophobic region, has the same activity, and is expressed in placental tissues. In general longer isoform contains 2 SH2 domains, a SH3 domain, a pleckstrin homology (PH) domain, and a calcium-dependent phospholipid-binding C2 domain. The C-terminus contains the catalytic domain of RasGap which catalyzes the activation of Ras by hydrolyzing GTP-bound active Ras into an inactive GDP-bound form of Ras. This model contains the C-terminal SH2 domain. In general SH2 domains are involved in signal transduction. They typically bind pTyr-containing ligands via two surface pockets, a pTyr and hydrophobic binding pocket, allowing proteins with SH2 domains to localize to tyrosine phosphorylated sites.

                          10        20        30        40        50        60
                  ....*....|....*....|....*....|....*....|....*....|....*....|..
gi 2462512593 378 PWFHGKLSRREAEALLQLN---GDFLVRtkdhrfESVSH----LISYHMDN---HLPIISAG 429
Cdd:cd10354     1 IWFHGKISREEAYNMLVKVggpGSFLVR------ESDNTpgdySLSFRVNEgikHFKIIPTG 56

X11-like Phosphotyrosine-binding (PTB) domain; The function of the neuronal protein X11 is unknown to date. X11 has a PTB domain followed by two PDZ domains. PTB domains have a common PH-like fold and are found in various eukaryotic signaling molecules. This domain was initially shown to binds peptides with a NPXY motif with differing requirements for phosphorylation of the tyrosine, although more recent studies have found that some types of PTB domains can bind to peptides lack tyrosine residues altogether. In contrast to SH2 domains, which recognize phosphotyrosine and adjacent carboxy-terminal residues, PTB-domain binding specificity is conferred by residues amino-terminal to the phosphotyrosine. PTB domains are classified into three groups: phosphotyrosine-dependent Shc-like, phosphotyrosine-dependent IRS-like, and phosphotyrosine-independent Dab-like PTB domains. This cd is part of the Dab-like subgroup.

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                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 2462512593  49 GVSYLVRYMGCVEVLqSMRALDFNTRTQVTREAISLVcEAVPGAkgatrrrkpcSRPLSsilgrsnlkfagmPITLTVST 128
Cdd:cd01208     7 GVIFGANYLGSTQLL-SERNPSKNVRMAQAQEAVSRV-KAPEGE----------SQPST-------------EVDLFIST 61

                          90       100       110       120       130       140       150       160
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 2462512593 129 SSLNLMAADCKQIIANHHMQSISF----------------ASGGDPDTAEYVAYVAKDPVNQRA-CHILECPEglAQDVI 191
Cdd:cd01208    62 ERIKVLNADTQETMMDHALRTISYiadignivvlmarrrmPRSSSQECVETTPPSQEGKRQYKMiCHVFESED--AQLIA 139

                         170
                  ....*....|....*.
gi 2462512593 192 STIGQAFELRFKQYLR 207
Cdd:cd01208   140 QSIGQAFSVAYQEFLR 155

Src homology 2 domain found in the SH2 domain containing protein 4A (SH2D4A); SH2D4A contains a single SH2 domain. In general SH2 domains are involved in signal transduction. They typically bind pTyr-containing ligands via two surface pockets, a pTyr and hydrophobic binding pocket, allowing proteins with SH2 domains to localize to tyrosine phosphorylated sites.

                          10        20        30
                  ....*....|....*....|....*....|.
gi 2462512593 377 EPWFHGKLSRREAEALL--QLNGDFLVRTKD 405
Cdd:cd10350     7 APWFHGILTLKKANELLlsTMPGSFLIRVSE 37

Src homology 2 domain found in the SH2 domain containing protein 7 (SH2D7); SH2D7 contains a single SH2 domain. In general SH2 domains are involved in signal transduction. They typically bind pTyr-containing ligands via two surface pockets, a pTyr and hydrophobic binding pocket, allowing proteins with SH2 domains to localize to tyrosine phosphorylated sites.

                          10        20        30        40
                  ....*....|....*....|....*....|....*....|..
gi 2462512593 378 PWFHGKLSRREAEALL--QLNGDFLVRTKDhrfESVSHLISY 417
Cdd:cd10417     8 PWFHGFITRKQTEQLLrdKALGSFLIRLSD---RATGYILSY 46

Src homology 2 (SH2) domain found in the growth factor receptor bound, subclass 14 (Grb14) proteins; The Grb family binds to the epidermal growth factor receptor (EGFR, erbB1) via their SH2 domains. Grb14 is part of the Grb7 family of proteins which also includes Grb7, and Grb14. They are composed of an N-terminal Proline-rich domain, a Ras Associating-like (RA) domain, a Pleckstrin Homology (PH) domain, a phosphotyrosine interaction region (PIR, BPS) and a C-terminal SH2 domain. The SH2 domains of Grb7, Grb10 and Grb14 preferentially bind to a different RTK. Grb14 binds to Fibroblast Growth Factor Receptor (FGFR) and weakly to the erbB2 receptor. In general SH2 domains are involved in signal transduction. They typically bind pTyr-containing ligands via two surface pockets, a pTyr and hydrophobic binding pocket, allowing proteins with SH2 domains to localize to tyrosine phosphorylated sites.

                          10        20        30
                  ....*....|....*....|....*....|..
gi 2462512593 375 RGEPWFHGKLSRREAEALL----QLNGDFLVR 402
Cdd:cd10414     3 RSQPWFHHKISRDEAQRLIiqqgLVDGVFLVR 34