RNA polymerase-associated protein CTR9 homolog (CTR9)

RNA polymerase-associated protein CTR9 homolog (CTR9) is a conserved scaffold protein and core subunit of the Paf1 complex (Paf1C), which binds RNA polymerase II and is essential for transcription elongation, histone modification, and the regulation of gene expression. CTR9’s interaction with Paf1 is necessary for proper assembly and stability of the Paf1 complex, which in turn regulates multiple aspects of RNA processing, cell cycle progression, and chromatin structure. In yeast and humans, loss of CTR9 leads to severe cellular phenotypes, including chromosome instability, reduced expression of cell cycle genes, telomere defects, and impaired cell fitness. The Paf1 complex, with CTR9 as a central structural determinant, orchestrates communication between transcriptional activators, histone methyltransferases, RNA processing machinery, and termination factors, thereby ensuring precise gene expression and genome integrity. Disruption of CTR9 or Paf1 complex function is linked to oncogenesis and may impact telomere biology, but CTR9 itself is not currently a direct therapeutic target nor widely used as a clinical biomarker.

Other names

CTR9KIAA0155SH2BP1TSBPp150p150TSPSH2 domain-binding protein 1Paf1/RNA polymerase II complex componentRNA polymerase-associated protein CTR9 homologCtr9 homologTPR-containing, SH2-binding phosphoprotein