The second LIM domain of LIMK2 (LIM domain Kinase 2)
The second LIM domain of LIMK2 (LIM domain Kinase 2): LIMK2 is a member of the LIMK protein family, which comprises LIMK1 and LIMK2. LIMK contains two LIM domains, a PDZ domain, and a kinase domain. LIMK is involved in the regulation of actin polymerization and microtubule disassembly. LIMK influences architecture of the actin cytoskeleton by regulating the activity of the cofilin family proteins cofilin1, cofilin2, and destrin. The mechanism of the activation is to phosphorylates cofilin on serine 3 and inactivates its actin-severing activity, altering the rate of actin depolymerisation. LIMK activity is activated by phosphorylation of a threonine residue within the activation loop of the kinase by p21-activated kinases 1 and 4 and by Rho kinase. LIMKs can function in both cytoplasm and nucleus. Both LIMK1 and LIMK2 can act in the nucleus to suppress Rac/Cdc42-dependent cyclin D1 expression. LIMK2 is expressed in all tissues. While LIMK1 localizes mainly at focal adhesions, LIMK2 is found in cytoplasmic punctae, suggesting that they may have different cellular functions. The activity of LIM kinase 2 to regulate cofilin phosphorylation is inhibited by the direct binding of Par-3. LIMK2 activation promotes cell cycle progression. The phenotype of Limk2 knockout mice shows a defect in spermatogenesis. The LIM domains have been shown to play an important role in regulating kinase activity and likely also contribute to LIMK function by acting as sites of protein-to-protein interactions. All LIM domains are 50-60 amino acids in size and share two characteristic zinc finger motifs. The two zinc fingers contain eight conserved residues, mostly cysteines and histidines, which coordinately bond to two zinc atoms. LIM domains function as adaptors or scaffolds to support the assembly of multimeric protein complexes.
Structure:1X6A_A: Human LIMK2 LIM2 domain binds Zn - View structure with Cn3D
Comment:The two zinc fingers contain eight conserved residues, mostly cysteines and histidines, which coordinately bond to two zinc atoms. The Zn binding residues of LIM domain are highly conserved.
Jiyao W et al.(2023). "The conserved domain database in 2023.",