Alternative titles; symbols
HGNC Approved Gene Symbol: WASHC1
Cytogenetic location: 9p24.3 Genomic coordinates (GRCh38): 9:14,513-30,487 (from NCBI)
WASHC1 is a component of the WASH complex, which is involved in regulation of endosomal protein sorting (Jia et al., 2010).
Linardopoulou et al. (2007) cloned WASH1, which they called WASH. The deduced protein contains 468 amino acids. WASH has 2 WASH homology domains (WHD1 and WHD2) in its N-terminal half. In its C-terminal half, WASH has a proline-rich stretch followed by a WH2 actin (see 102560)-binding domain (V), a central region (C), and an acidic stretch (A) that together form the VCA module found in all WASP proteins (see WASF1; 605035). The VCA module mediates binding to actin and the ARP2/3 protein complex (604221) and stimulates actin nucleation. Northern blot analysis detected an approximately 1.8-kb transcript in all tissues examined. RNA dot blot analysis and RT-PCR confirmed ubiquitous and variable WASH1 expression. Database analysis revealed WASH orthologs in both vertebrates and invertebrates. Vertebrates showed highest conservation in the WASH C terminus. Fluorescence-tagged WASH1 colocalized with cytoskeletal actin and accumulated in filopodia and lamellipodia.
Using Western blot analysis of Jurkat human T cells, Gomez and Billadeau (2009) detected WASH at an apparent molecular mass of 70 kD. HeLa cells expressed a WASH isoform lacking the N-terminal region. Immunohistochemical analysis revealed a punctate cytoplasmic WASH distribution in Jurkat, HeLa, and U-87MG glioblastoma cell lines.
Copy Number Variation
Linardopoulou et al. (2007) identified numerous subtelomeric copies of the WASH gene distributed among multiple human chromosomes. FISH analysis revealed variation in their copy number and location among primate species and human individuals. Sequencing of long-range PCR products from 3 unrelated individuals revealed up to 5 potentially functional WASH variants and multiple pseudogenes per individual human genome.
Linardopoulou et al. (2007) determined that the WASH1 gene contains 11 exons and spans 15 kb. The first exon is noncoding and lies within a CpG island.
By genomic sequence analysis, Linardopoulou et al. (2007) mapped the WASH1 gene to the subtelomeric region of chromosome 9p, where it ends within 5 kb of the telomere array. Linardopoulou et al. (2007) identified WASH pseudogenes on similar subtelomeric regions of chromosomes 15q, 1p, Xq/Yq, and 16p. The single-copy mouse Wash ortholog maps to an internal location on chromosome 17.
Gross (2022) mapped the WASHC1 gene to chromosome 9p24.3 based on an alignment of the WASHC1 sequence (GenBank NM_001378090) with the genomic sequence (GRCh38).
Linardopoulou et al. (2007) found that the isolated VCA module of recombinant human WASH1 stimulated in vitro actin polymerization in the presence of the ARP2/3 complex.
Gomez and Billadeau (2009) found that WASH was required for retrograde transport of cation-independent mannose-6-phosphate receptor (IGF2R; 147280) via the retromer complex (see 601272). WASH functioned in a multiprotein complex of over 600 kD that also contained FAM21 (see 613631) and APR2/3. Mutation analysis revealed that the N terminus of WASH interacted with FAM21, the WHD2 domain interacted with alpha-tubulin (see 602529), and the VCA region interacted with actin. WASH interaction with FAM21 was required for its endosomal localization. Knockdown of WASH blocked retromer-mediated endosome sorting.
Jia et al. (2010) stated that WASH localizes to endosomal subdomains and regulates endocytic vesicle scission in an ARP2/3-dependent manner. Using affinity purification, immunoprecipitation, and knockdown experiments, Jia et al. (2010) found that WASH, FAM21, SWIP (WASHC4; 615748), strumpellin (WASHC5; 610657), and CCDC53 (WASHC3; 619925) formed a high-affinity WASH regulatory core complex (SHRC) in human, cow, and fly. Immunofluorescence analysis in transfected HeLa cells showed that SHRC subunits colocalized with each other and with a subset of EEA1 (605070)-positive endosomes, similar to endogenous WASH. Using recombinant proteins, the authors found that the SHRC inhibited intrinsic WASH activity toward the ARP2/3 complex. The N-terminal coiled-coil domain of WASH was required for association with all components of the SHRC. The conserved helical domain of CCDC53 was necessary and sufficient for association of CCDC53 with all other SHRC components and could stabilize WASH in HeLa cell lysates. The C terminus of SWIP mediated interaction with strumpellin. The N-terminal domain of FAM21 interacted with all components of the SHRC, whereas the C-terminal domain of FAM21 interacted directly with CAPZ (see 601580) and inhibited its anti-capping activity. Moreover, the C-terminal domain of FAM21 interacted directly with phospholipids and phosphatidylserine, potentially linking the SHRC to endosomal domains enriched in phospholipids.
Seaman et al. (2013) reviewed the role of the WASH complex in endosomal protein sorting.
Verboon et al. (2015) showed that Wash1 functioned downstream of Rho1 GTPase, an ortholog of RHOA (165390), to regulate developmental migration of posteriorly located Drosophila immune cells, or hemocytes, toward the head. This hemocyte migration required activation of the Arp2/3 complex, but it did not require other members of the WASH complex.
Bartuzi et al. (2016) showed that WASH components colocalize and interact with the LDL receptor (LDLR; 606945). The WASH complex associates with the CCC complex (COMMD, see 607238; CCDC22, 300859; CCDC93, 620553) and recruits it to endosomes. LDLR is an endosomal cargo of the CCC-associated WASH complex, and inactivation of the WASH complex caused LDLR mislocalization, increased lysosomal degradation of the LDLR, and impaired LDL uptake.
Linardopoulou et al. (2007) found that knockout of the Drosophila WASH ortholog, which they called washout, was early embryonic lethal.
To avoid early embryonic lethality, Xia et al. (2014) generated adult mice with tamoxifen-dependent loss of Wash. Wash-deficient adult mice showed weight loss and severe anemia. Expression of mouse Wash was mainly nuclear in long-term hematopoietic cells (HSCs), both nuclear and cytoplasmic in short-term HSCs, and primarily cytoplasmic in multipotent progenitor cells. Conditional deletion of Wash in bone marrow resulted in etiolation of feet and ears accompanied by severe anemia, blood cytopenia, thrombocytopenia, and neutropenia, and 60% of these mice died over the 8-week observation period. Bone marrow cells of Wash-knockout mice had an expanded pool of long-term HSCs that were defective in their ability to differentiate into all types of mature blood lineages. Wash deficiency resulted in downregulation of Myc (190080) expression. Restoration of Wash or Myc led to a restoration of long-term HSC differentiation. Chromatin immunoprecipitation analysis indicated that Wash interacted with the Myc promoter and recruited the nucleosome-remodeling factor (NURF) complex (see 601819) to activate Myc in an actin-nucleation-dependent manner. Xia et al. (2014) concluded that WASH is necessary for MYC activation and differentiation of long-term HSCs.
Bartuzi, P., Billadeau, D. D., Favier, R., Rong, S., Dekker, D., Fedoseienko, A., Fieten, H., Wijers, M., Levels, J. H., Huijkman, N., Kloosterhuis, N., van der Molen, H., and 11 others. CCC- and WASH-mediated endosomal sorting of LDLR is required for normal clearance of circulating LDL. Nature Commun. 7: 10961, 2016. [PubMed: 26965651] [Full Text: https://doi.org/10.1038/ncomms10961]
Gomez, T. S., Billadeau, D. D. A FAM21-containing WASH complex regulates retromer-dependent sorting. Dev. Cell 17: 699-711, 2009. [PubMed: 19922874] [Full Text: https://doi.org/10.1016/j.devcel.2009.09.009]
Gross, M. B. Personal Communication. Baltimore, Md. 6/21/2022.
Jia, D., Gomez, T. S., Metlagel, Z., Umetani, J., Otwinowski, Z., Rosen, M. K., Billadeau, D. D. WASH and WAVE actin regulators of the Wiskott-Aldrich syndrome protein (WASP) family are controlled by analogous structurally related complexes. Proc. Nat. Acad. Sci. 107: 10442-10447, 2010. [PubMed: 20498093] [Full Text: https://doi.org/10.1073/pnas.0913293107]
Linardopoulou, E. V., Parghi, S. S., Friedman, C., Osborn, G. E., Parkhurst, S. M., Trask, B. J. Human telomeric WASH genes encode a new subclass of the WASP family. PLoS Genet. 3: e237, 2007. Note: Electronic Article. [PubMed: 18159949] [Full Text: https://doi.org/10.1371/journal.pgen.0030237]
Seaman, M. N. J., Gautreau, A., Billadeau, D. D. Retromer-mediated endosomal protein sorting: all WASHed up! Trends Cell Biol. 23: 522-528, 2013. [PubMed: 23721880] [Full Text: https://doi.org/10.1016/j.tcb.2013.04.010]
Verboon, J. M., Rahe, T. K., Rodriguez-Mesa, E., Parkhurst, S. M. Wash functions downstream of Rho1 GTPase in a subset of Drosophila immune cell developmental migrations. Molec. Biol. Cell 26: 1665-1674, 2015. [PubMed: 25739458] [Full Text: https://doi.org/10.1091/mbc.E14-08-1266]
Xia, P., Wang, S., Huang, G., Zhu, P., Li, M., Ye, B., Du, Y., Fan, Z. WASH is required for the differentiation commitment of hematopoietic stem cells in a c-Myc-dependent manner. J. Exp. Med. 211: 2119-2134, 2014. [PubMed: 25225459] [Full Text: https://doi.org/10.1084/jem.20140169]