Alternative titles; symbols
HGNC Approved Gene Symbol: SWSAP1
Cytogenetic location: 19p13.2 Genomic coordinates (GRCh38): 19:11,374,666-11,376,169 (from NCBI)
Homologous recombination repair is a well-conserved cellular process for the repair of DNA lesions that uses the intact sister chromatid as a template. SWSAP1 forms a heterodimer with SWS1 (ZSWIM7; 614535) that functions in homologous recombination repair (Liu et al., 2011).
By PCR, Liu et al. (2011) cloned human SWSAP1. The deduced 229-amino acid protein contains Walker A and Walker B nucleotide-binding boxes in its N-terminal half, suggesting that it functions as an ATPase.
Liu et al. (2011) found that SWSAP1 affinity purified with SWS1 from HEK293T cells. The heterodimeric SWS1-SWSAP1 complex had an apparent molecular mass of about 40 kD. Expression of either epitope-tagged SWSAP1 or SWS1 was enhanced upon coexpression. Conversely, knockdown of either SWS1 or SWSAP1 expression via small interfering RNA led to a dramatic decrease in the level of the other protein. SWSAP1 or the SWSAP1-SWS1 complex hydrolyzed ATP in vitro, and activity was significantly increased in the presence of single-stranded DNA compared with double-stranded DNA. SWSAP1 or the SWS1-SWSAP1 complex, but not SWS1 alone, bound DNA in an ATP-independent manner. Knockdown of SWS1 or SWSAP1 increased cell sensitivity to the DNA damaging agent methylmethane sulfonate (MMS) and reduced RAD51 (see 179617) foci formation. Double knockdown of SWSAP1 and RAD51C (602774) further increased MMS sensitivity and further reduced RAD51 foci formation compared with SWSAP1 or RAD51C single-knockdown cells, indicating that SWS1-SWSAP1 and RAD51 likely represent independent subpathways of homologous recombination.
Hartz (2012) mapped the SWSAP1 gene to chromosome 19p13.2 based on an alignment of the SWSAP1 sequence (GenBank AK092438) with the genomic sequence (GRCh37).
Hartz, P. A. Personal Communication. Baltimore, Md. 3/14/2012.
Liu, T., Wan, L., Wu, Y., Chen, J., Huang, J. hSWS1-SWSAP1 is an evolutionarily conserved complex required for efficient homologous recombination repair. J. Biol. Chem. 286: 41758-41766, 2011. [PubMed: 21965664] [Full Text: https://doi.org/10.1074/jbc.M111.271080]