title: PCNA-dependent regulation of p21 ubiquitylation and degradation via the CRL4Cdt2 ubiquitin ligase complex.
abstract: The DNA polymerase delta processivity factor Proliferating Cell Nuclear Antigen (PCNA) promotes the DNA damage-induced degradation of the replication initiation factor Cdt1 via the CRL4(Cdt2) E3 ubiquitin ligase complex. Here we demonstrate that PCNA promotes the ubiquitylation and degradation of the CDK inhibitor p21 in cells irradiated with low dose of ultraviolet (UV) by a similar mechanism. Human cells that are depleted of Cul4, DDB1 (damage-specific DNA-binding protein-1), or the DCAF Cdt2, are deficient in the UV-induced ubiquitylation and degradation of p21. Depletion of mammalian cells of PCNA by siRNA, or mutations in p21 that abrogate PCNA binding, prevent UV-induced p21 ubiquitylation and degradation, indicating that physical binding with PCNA is necessary for the efficient ubiquitylation of p21 via the CRL4(Cdt2) ubiquitin ligase. Cdt2 functions as the substrate recruiting factor for p21 to the rest of the CRL4 ubiquitin ligase complex. The CRL4(Cdt2) E3 ubiquitin ligase ubiquitylates p21 both in vivo and in vitro, and its activity is dependent on the interaction of p21 with PCNA. Finally, we show that the CRL4(Cdt2) and the SCF(Skp2) ubiquitin ligases are redundant with each other in promoting the degradation of p21 during an unperturbed S phase of the cell cycle.
authors.affiliation: Department of Biochemistry and Molecular Genetics, University of Virginia, School of Medicine, Charlottesville, Virginia 22908, USA.
authors.forename: Tarek
authors.initials: T
authors.lastname: Abbas
authors.forename: Uma
authors.initials: U
authors.lastname: Sivaprasad
authors.forename: Kenta
authors.initials: K
authors.lastname: Terai
authors.forename: Virginia
authors.initials: V
authors.lastname: Amador
authors.forename: Michele
authors.initials: M
authors.lastname: Pagano
authors.forename: Anindya
authors.initials: A
authors.lastname: Dutta
mesh_terms: D001483:Base Sequence; D050759:Cyclin-Dependent Kinase Inhibitor p21 / Q000378:metabolism*; D006801:Humans; D006868:Hydrolysis; D018809:Proliferating Cell Nuclear Antigen / Q000502:physiology*; D046988:Proteasome Endopeptidase Complex / Q000378:metabolism; D034622:RNA Interference; D034741:RNA, Small Interfering; D016196:S Phase; D044786:S-Phase Kinase-Associated Proteins / Q000378:metabolism; D044767:Ubiquitin-Protein Ligases / Q000378:metabolism*; D054875:Ubiquitination; D014466:Ultraviolet Rays
chemical_list: C493956:CDKN1A protein, human; D050759:Cyclin-Dependent Kinase Inhibitor p21; D018809:Proliferating Cell Nuclear Antigen; D034741:RNA, Small Interfering; D044786:S-Phase Kinase-Associated Proteins; D044767:Ubiquitin-Protein Ligases; D046988:Proteasome Endopeptidase Complex
references.citation: Biochemistry. 2005 Nov 8;44(44):14553-64
references.pmid: 16262255
references.citation: Mol Cell. 2002 Dec;10(6):1511-8
references.pmid: 12504025
references.citation: Oncogene. 1998 Nov 12;17(19):2437-44
references.pmid: 9824154
references.citation: Nat Cell Biol. 2006 Jan;8(1):84-90
references.pmid: 16362051
references.citation: J Biol Chem. 2006 Mar 10;281(10):6246-52
references.pmid: 16407252
references.citation: Cell Cycle. 2006 Aug;5(15):1675-80
references.pmid: 16861906
references.citation: Mol Cell Biol. 2007 Apr;27(8):3187-98
references.pmid: 17283049
references.citation: Proc Natl Acad Sci U S A. 1998 Sep 15;95(19):11324-9
references.pmid: 9736735
references.citation: Nat Cell Biol. 2003 Nov;5(11):1008-15
references.pmid: 14578910
references.citation: Mol Cell. 2007 Aug 3;27(3):462-73
references.pmid: 17679094
references.citation: Mol Cell. 2006 Sep 1;23(5):709-21
references.pmid: 16949367
references.citation: Science. 2004 Feb 27;303(5662):1371-4
references.pmid: 14739464
references.citation: Nat Cell Biol. 2003 Nov;5(11):1001-7
references.pmid: 14528312
references.citation: Genes Dev. 2006 Nov 15;20(22):3117-29
references.pmid: 17085480
references.citation: J Biol Chem. 2006 Feb 17;281(7):3753-6
references.pmid: 16407242
references.citation: EMBO J. 1997 Aug 15;16(16):4851-8
references.pmid: 9305627
references.citation: Nat Cell Biol. 2004 Oct;6(10):1003-9
references.pmid: 15448697
references.citation: J Biol Chem. 2003 Jul 11;278(28):25752-7
references.pmid: 12730199
references.citation: J Biol Chem. 2005 Aug 12;280(32):29282-8
references.pmid: 15964852
references.citation: Mol Cell Biol. 2008 Jan;28(1):177-87
references.pmid: 17967871
references.citation: J Exp Med. 2005 Jul 4;202(1):157-68
references.pmid: 15998794
references.citation: Mol Cell. 2004 Dec 3;16(5):839-47
references.pmid: 15574338
references.citation: Cell. 2003 Sep 5;114(5):599-610
references.pmid: 13678583
references.citation: Science. 1998 Nov 20;282(5393):1497-501
references.pmid: 9822382
references.citation: J Biol Chem. 2003 Nov 7;278(45):44312-9
references.pmid: 12952966
references.citation: Oncogene. 2008 Jul 3;27(29):4056-64
references.pmid: 18332868
references.citation: Cell Cycle. 2006 Aug;5(15):1719-29
references.pmid: 16861890
references.citation: Oncogene. 1998 Jan 22;16(3):311-20
references.pmid: 9467956
references.citation: EMBO Rep. 2006 Nov;7(11):1134-9
references.pmid: 17039252
references.citation: Mol Cell Biol. 2000 Nov;20(22):8602-12
references.pmid: 11046155
references.citation: J Biol Chem. 2006 Sep 15;281(37):26876-83
references.pmid: 16803887
references.citation: Nature. 1995 Oct 12;377(6549):552-7
references.pmid: 7566157
references.citation: EMBO J. 2006 Mar 8;25(5):1126-36
references.pmid: 16482215