Single Stranded DNA Binding Protein 1 (SSBP1)

SSBP1 is a housekeeping gene involved in mitochondrial biogenesis. It is also a subunit of a single-stranded DNA binding complex involved in the maintenance of genome stability.Coimmunoprecipitation analysis confirmed that SOSS complexes formed in HeLa cells independent of DNA damage. SOSSA served as the central assembly factor, and SOSSB and SOSSC bound overlapping regions on SOSSA, but they did not interact directly with each other. Depletion of SOSSA by small interfering RNA led to dramatic decreases in SOSSB1 and SOSSB2 protein levels, abrogated targeting of SOSSB1 and SOSSB2 to chromatin, increased ionizing radiation sensitivity, caused defective G2/M checkpoint, and impaired homologous recombination repair.