title: UbE2E1/UBCH6 Is a Criticalin VivoE2 for the PRC1-catalyzed Ubiquitination of H2A at Lys-119.
abstract: UbE2E1/UbcH6 is an E2 ubiquitin-conjugating enzyme that is regulated by USP7. We identified UbE2E1 as a novel component of Polycomb repressive complex 1 (PRC1), the E3 ligase complex responsible for histone H2A ubiquitination and gene silencing. We demonstrate that UbE2E1 is critical for the monoubiquitination of H2A at residue Lys-119 (uH2AK119) through its association with the PRC1 complex. UbE2E1 interacts with PRC1 subunits including Ring1A and Ring1B. Overexpression of UbE2E1 results in increased levels of uH2AK119, whereas overexpression of catalytically inactive UbE2E1_C131A or UbE2E1 knockdown results in decreased levels of uH2AK119. The down-regulation of H2A ubiquitination by loss of function of UbE2E1 is correlated with alleviated p16INK4apromoter repression and induced growth inhibition in HCT116 cells. These results are specific to UbE2E1 as knockdown of UbE2D E2s does not show any effect on uH2AK119. We extended the UbE2E1 regulation of uH2AK119 to USP7 and showed that USP7 is also a key regulator for monoubiquitination at H2A Lys-119 as both knockdown and deletion of USP7 results in decreased levels of uH2AK119. This study reveals that UbE2E1 is anin vivoE2 for the PRC1 ligase complex and thus plays an important role in the regulation of H2A Lys-119 monoubiquitination.
authors.affiliation: From the Department of Biology, York University, Toronto, Ontario M3J1P3 and.
authors.forename: Keith
authors.initials: K
authors.lastname: Wheaton
authors.affiliation: From the Department of Biology, York University, Toronto, Ontario M3J1P3 and.
authors.forename: Feroz
authors.initials: F
authors.lastname: Sarkari
authors.affiliation: From the Department of Biology, York University, Toronto, Ontario M3J1P3 and.
authors.forename: Beena
authors.initials: B
authors.lastname: Stanly Johns
authors.affiliation: From the Department of Biology, York University, Toronto, Ontario M3J1P3 and.
authors.forename: Hossein
authors.initials: H
authors.lastname: Davarinejad
authors.affiliation: From the Department of Biology, York University, Toronto, Ontario M3J1P3 and.
authors.forename: Olga
authors.initials: O
authors.lastname: Egorova
authors.affiliation: the Princess Margaret Cancer Centre, University Health Network, Toronto, Ontario M5G 1L7, Canada.
authors.forename: Lilia
authors.initials: L
authors.lastname: Kaustov
authors.affiliation: the Princess Margaret Cancer Centre, University Health Network, Toronto, Ontario M5G 1L7, Canada.
authors.forename: Brian
authors.initials: B
authors.lastname: Raught
authors.affiliation: From the Department of Biology, York University, Toronto, Ontario M3J1P3 and.
authors.forename: Vivian
authors.initials: V
authors.lastname: Saridakis
authors.affiliation: From the Department of Biology, York University, Toronto, Ontario M3J1P3 and yisheng@yorku.ca.
authors.forename: Yi
authors.initials: Y
authors.lastname: Sheng
mesh_terms: D002384:Catalysis; D018797:Cell Cycle Proteins / Q000378:metabolism*; D045744:Cell Line, Tumor; D019941:Cyclin-Dependent Kinase Inhibitor p16 / Q000235:genetics; D020868:Gene Silencing; D006657:Histones / Q000737:chemistry / Q000378:metabolism*; D006801:Humans; D008239:Lysine / Q000378:metabolism*; D011485:Protein Binding; D043222:Ubiquitin Thiolesterase / Q000235:genetics / Q000378:metabolism; D044763:Ubiquitin-Conjugating Enzymes / Q000235:genetics / Q000378:metabolism*; D000076084:Ubiquitin-Specific Peptidase 7; D054875:Ubiquitination
chemical_list: D018797:Cell Cycle Proteins; D019941:Cyclin-Dependent Kinase Inhibitor p16; D006657:Histones; C116662:PRC1 protein, human; C489963:UBE2E1 protein, human; D044763:Ubiquitin-Conjugating Enzymes; C464569:USP7 protein, human; D043222:Ubiquitin Thiolesterase; D000076084:Ubiquitin-Specific Peptidase 7; D008239:Lysine
keywords: Polycomb repressive complex; deubiquitylation (deubiquitination); gene silencing; h2a ubiquitination; histone modification; uH2AK119; ubiquitin-conjugating enzyme (E2 enzyme); ubiquitylation (ubiquitination)