title: Transcription-independent function of Polycomb group protein PSC in cell cycle control.
abstract: Polycomb group (PcG) proteins control development and cell proliferation through chromatin-mediated transcriptional repression. We describe a transcription-independent function for PcG protein Posterior sex combs (PSC) in regulating the destruction of cyclin B (CYC-B). A substantial portion of PSC was found outside canonical PcG complexes, instead associated with CYC-B and the anaphase-promoting complex (APC). Cell-based experiments and reconstituted reactions established that PSC and Lemming (LMG, also called APC11) associate and ubiquitylate CYC-B cooperatively, marking it for proteosomal degradation. Thus, PSC appears to mediate both developmental gene silencing and posttranslational control of mitosis. Direct regulation of cell cycle progression might be a crucial part of the PcG system's function in development and cancer.
authors.affiliation: Department of Biochemistry and Centre for Biomedical Genetics, Erasmus University Medical Centre, Post Office Box 1738, 3000 DR, Rotterdam, Netherlands.
authors.forename: Adone
authors.initials: A
authors.lastname: Mohd-Sarip
authors.forename: Anna
authors.initials: A
authors.lastname: Lagarou
authors.forename: Cecile M
authors.initials: CM
authors.lastname: Doyen
authors.forename: Jan A
authors.initials: JA
authors.lastname: van der Knaap
authors.forename: Ülkü
authors.initials: Ü
authors.lastname: Aslan
authors.forename: Karel
authors.initials: K
authors.lastname: Bezstarosti
authors.forename: Yasmin
authors.initials: Y
authors.lastname: Yassin
authors.forename: Hugh W
authors.initials: HW
authors.lastname: Brock
authors.forename: Jeroen A A
authors.initials: JA
authors.lastname: Demmers
authors.forename: C Peter
authors.initials: CP
authors.lastname: Verrijzer
mesh_terms: D064173:Anaphase-Promoting Complex-Cyclosome; D000818:Animals; D064198:Apc11 Subunit, Anaphase-Promoting Complex-Cyclosome; D002352:Carrier Proteins / Q000378:metabolism; D059447:Cell Cycle Checkpoints; D002460:Cell Line; D054910:Compound Eye, Arthropod / Q000254:growth & development / Q000378:metabolism; D019926:Cyclin B / Q000378:metabolism*; D004268:DNA-Binding Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D029721:Drosophila Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D004331:Drosophila melanogaster / Q000166:cytology / Q000196:embryology / Q000378:metabolism; D059565:G2 Phase Cell Cycle Checkpoints; D020868:Gene Silencing; D060227:Imaginal Discs / Q000378:metabolism; D008938:Mitosis; D010641:Phenotype; D063150:Polycomb Repressive Complex 1; D046988:Proteasome Endopeptidase Complex / Q000378:metabolism; D011485:Protein Binding; D054730:Protein Interaction Domains and Motifs; D034622:RNA Interference; D014158:Transcription, Genetic; D043743:Ubiquitin-Protein Ligase Complexes / Q000378:metabolism; D054875:Ubiquitination; D014921:Wings, Animal / Q000254:growth & development
chemical_list: D002352:Carrier Proteins; C503698:CycB protein, Drosophila; D019926:Cyclin B; D004268:DNA-Binding Proteins; D029721:Drosophila Proteins; C066770:Pc protein, Drosophila; C071050:Psc protein, Drosophila; D043743:Ubiquitin-Protein Ligase Complexes; D064173:Anaphase-Promoting Complex-Cyclosome; D064198:Apc11 Subunit, Anaphase-Promoting Complex-Cyclosome; D063150:Polycomb Repressive Complex 1; C577352:lmgA protein, Drosophila; D046988:Proteasome Endopeptidase Complex