UV Stimulated Scaffold Protein A (UVSSA)

UV-sensitive syndrome (UVSS) is a genodermatosis characterized by cutaneous photosensitivity without skin carcinoma. Despite mild clinical features, cells from individuals with UVSS, like Cockayne syndrome cells, are very UV sensitive and are deficient in transcription-coupled nucleotide-excision repair (TC-NER), which removes DNA damage in actively transcribed genes. Three of the seven known UVSS cases carry mutations in the Cockayne syndrome genes ERCC8 or ERCC6. The remaining four individuals with UVSS, one of whom is described for the first time here, formed a separate UVSS-A complementation group; however, the responsible gene was unknown. The UVSSA protein interacts with TC-NER machinery and stabilizes the ERCC6 complex; it also facilitates ubiquitination of RNA polymerase IIo stalled at DNA damage sites.