GT198 is a human oncogene (gene symbol PSMC3IP, alias TBPIP or Hop2)[1] located within the BRCA1 locus at chromosome 17q21.[2][3] It encodes protein product named GT198, Hop2 or TBPIP. The GT198 gene is found to be mutated with its protein overexpressed in human cancers including breast and ovarian cancers.[4][5]
GT198 acts as a DNA repair factor responsible for error-free repair of DNA double-strand breaks.[6][7][8] GT198 also controls gene regulation, including steroid hormone-mediated gene activation as a steroid hormone receptorcoactivator.[3]
Similar to BRCA1, GT198 is a breast and ovarian cancer susceptibility gene with germline mutations found in a small percentage of early-onset breast and ovarian cancer families.[9]
^Ijichi, H.; Tanaka, T.; Nakamura, T.; Yagi, H.; Hakuba, A.; Sato, M. (2000-05-02). "Molecular cloning and characterization of a human homologue of TBPIP, a BRCA1 locus-related gene". Gene. 248 (1–2): 99–107. doi:10.1016/s0378-1119(00)00141-4. ISSN0378-1119. PMID10806355.