title: UV-induced proteolysis of RNA polymerase II is mediated by VCP/p97 segregase and timely orchestration by Cockayne syndrome B protein.
abstract: RNA polymerase II (RNAPII) acts as a damage sensor for transcription-coupled nucleotide excision repair (TC-NER) and undergoes proteolytic clearance from damaged chromatin by the ubiquitin-proteasome system (UPS). Here, we report that Valosin-containing protein (VCP)/p97, a druggable oncotarget, is essential for RNAPII's proteolytic clearance in mammalian cells. We show that inhibition of VCP/p97, or siRNA-mediated ablation of VCP/p97 and its cofactors UFD1 and UBXD7 severely impairs ultraviolet radiation (UVR)-induced RNAPII degradation. VCP/p97 interacts with RNAPII, and the interaction is enhanced by Cockayne syndrome B protein (CSB). However, the VCP/p97-mediated RNAPII proteolysis occurs independent of CSB. Surprisingly, CSB enhances UVR-induced RNAPII ubiquitination but delays its turnover. Additionally, VCP/p97-mediated RNAPII turnover occurs with and without Von Hippel-Lindau tumor suppressor protein (pVHL), a known substrate receptor of Elongin E3 ubiquitin ligase for RNAPII. Moreover, pVHL re-expression improves cell viability following UVR. Whereas, VCP/p97 inhibition decreases cell viability and enhances a low-dose UVR killing in presence of pVHL. These findings reveal a function of VCP/p97 segregase in UVR-induced RNAPII degradation in mammalian cells, and suggest a role of CSB in coordinating VCP/p97-mediated extraction of ubiquitinated RNAPII and CSB itself from chromatin.
authors.affiliation: Department of Radiology, The Ohio State University, Columbus, OH 43210, USA.
authors.forename: Jinshan
authors.initials: J
authors.lastname: He
authors.affiliation: Department of Radiology, The Ohio State University, Columbus, OH 43210, USA.
authors.forename: Qianzheng
authors.initials: Q
authors.lastname: Zhu
authors.affiliation: Department of Radiology, The Ohio State University, Columbus, OH 43210, USA.
authors.forename: Gulzar
authors.initials: G
authors.lastname: Wani
authors.affiliation: Department of Radiology, The Ohio State University, Columbus, OH 43210, USA.|Department of Molecular and Cellular Biochemistry, The Ohio State University, Columbus, OH 43210, USA.|James Cancer Hospital and Solove Research Institute, The Ohio State University, Columbus, OH 43210, USA.
authors.forename: Altaf A
authors.initials: AA
authors.lastname: Wani
mesh_terms: D048868:Adaptor Proteins, Signal Transducing; D033942:Adaptor Proteins, Vesicular Transport; D000251:Adenosine Triphosphatases / Q000037:antagonists & inhibitors / Q000235:genetics / Q000378:metabolism*; D015153:Blotting, Western; D002352:Carrier Proteins / Q000235:genetics / Q000378:metabolism; D018797:Cell Cycle Proteins / Q000037:antagonists & inhibitors / Q000235:genetics / Q000378:metabolism*; D002460:Cell Line; D045744:Cell Line, Tumor; D002470:Cell Survival / Q000187:drug effects / Q000235:genetics / Q000528:radiation effects; D004265:DNA Helicases / Q000378:metabolism*; D045643:DNA Repair Enzymes / Q000378:metabolism*; D045325:HCT116 Cells; D006367:HeLa Cells; D006801:Humans; D047908:Intracellular Signaling Peptides and Proteins; D000075223:Poly-ADP-Ribose Binding Proteins; D011506:Proteins / Q000235:genetics / Q000378:metabolism; D059748:Proteolysis / Q000528:radiation effects; D011799:Quinazolines / Q000494:pharmacology; D034622:RNA Interference; D012319:RNA Polymerase II / Q000378:metabolism*; D013997:Time Factors; D054875:Ubiquitination / Q000528:radiation effects; D014466:Ultraviolet Rays; D000074405:Valosin Containing Protein; D051794:Von Hippel-Lindau Tumor Suppressor Protein / Q000378:metabolism
chemical_list: D048868:Adaptor Proteins, Signal Transducing; D033942:Adaptor Proteins, Vesicular Transport; D002352:Carrier Proteins; D018797:Cell Cycle Proteins; D047908:Intracellular Signaling Peptides and Proteins; C558357:N2,N4-dibenzylquinazoline-2,4-diamine; D000075223:Poly-ADP-Ribose Binding Proteins; D011506:Proteins; D011799:Quinazolines; C531895:UBXN7 protein, human; C491497:UFD1 protein, human; D051794:Von Hippel-Lindau Tumor Suppressor Protein; D012319:RNA Polymerase II; D000251:Adenosine Triphosphatases; D004265:DNA Helicases; C078673:ERCC6 protein, human; C000614178:VCP protein, human; D000074405:Valosin Containing Protein; D045643:DNA Repair Enzymes
keywords: RNA polymerase II; cockayne syndrome B; ubiquitin; valosin-containing protein; von hippel-lindau tumor suppressor protein