Transcription factor Clamp

UniProtKB accession:  Q9V9N4

Grouped By:  Matching UniProtKB accession

UniProtKB description:  Transcription factor involved in X-chromosome dosage compensation in males, the process by which transcription of the single X chromosome in the male is elevated (PubMed:23873939, PubMed:27414415, PubMed:27995349, PubMed:31320325, PubMed:34187599, PubMed:37602401). Binds to the DNA sequence (GA)n (PubMed:27414415, PubMed:28838946, PubMed:29281702). Clamp-binding promotes nucleosome depletion and chromatin accessibility, thereby allowing access to other transcription factors (PubMed:28838946, PubMed:29077765, PubMed:34187599). Specifically binds to cis-acting elements on the X-chromosome named chromatin entry sites and promotes recruitment of the male-specific lethal (MSL) histone acetyltransferase complex, which associates with actively transcribed genes on the male X-chromosome to upregulate their expression (PubMed:23873939, PubMed:27414415, PubMed:31320325). Mechanistically, acts by promoting chromatin accessibility at chromatin entry sites, facilitating DNA-binding of msl-2, followed by MSL complex recruitment (PubMed:31320325, PubMed:37602401). In addition to dosage compensation, also involved in zygotic genome activation (ZGA), a critical event in early embryonic development during which the developmental control passes from maternally provided mRNAs to the expression of the zygotic genome after fertilization (PubMed:34342574, PubMed:34849887). Maternally-provided protein cooperates with Zelda (zld) to activate zygotic transcription by increasing chromatin accessibility at promoters of specific genes and facilitate zld occupancy at a subset of key embryonic promoters (PubMed:34342574). Also acts as an activator of gypsy chromatin insulator function by promoting binding of Cp190 to chromatin (PubMed:30718365).