InterPro domain: IPR031101

This entry includes budding yeast RNA polymerase-associated protein Ctr9 and its homologues from other yeasts, animals and plants. The homologue in fission yeast is known as tetratricopeptide repeat protein 1 (Tpr1) [ 1 ].

Budding yeast Ctr9 is part of the Paf1 complex, an RNA polymerase II-associated protein complex containing Paf1, Cdc73, Ctr9, Rtf1 and Leo1 [ 2 ]. Paf1 complex is involved in histone modifications, transcription elongation and other gene expression processes that include transcript site selection [ 3 ]. Human Paf1 complex (Paf1C) consists of Paf1, Cdc73, Ctr9, Rtf1, Leo1 and Wdr61 (Ski8). As in yeast, the human Paf1C has a central role in co-transcriptional histone modifications [ 4 ].

Arabidopsis Paf1C related proteins such as VIP4 (Leo1), VIP5 (Rtf1), ELF7 (Paf1), ELF8 (Ctr9) and ATXR7 (Set1) are required for the induction of seed dormancy. They control both germination and flowering time [ 5 ].

1. The PAF complex and Prf1/Rtf1 delineate distinct Cdk9-dependent pathways regulating transcription elongation in fission yeast. PLoS Genet. 9, e1004029
2. Ctr9, Rtf1, and Leo1 are components of the Paf1/RNA polymerase II complex. Mol. Cell. Biol. 22, 1971-80
3. The human PAF1 complex acts in chromatin transcription elongation both independently and cooperatively with SII/TFIIS. Cell 140, 491-503
4. Workshop report from the Division of Research Grants, National Institutes of Health. The role of chromosome rearrangements, deletions, and point mutations in cancer--a Pathology B Study Section workshop. Cancer Res. 51, 5440-4
5. Identification of the Arabidopsis REDUCED DORMANCY 2 gene uncovers a role for the polymerase associated factor 1 complex in seed dormancy. PLoS ONE 6, e22241