title: c-Jun NH2-terminal kinase decreases ubiquitination and promotes stabilization of p21(WAF1/CIP1) in K562 cell.
abstract: Proteasome-dependent degradation of regulatory proteins is a known mechanism of cell cycle control. p21(WAF1/CIP1) (p21), a negative regulator of the cell division cycle, exhibits proteasome-sensitive turnover and ubiquitination. In the present study, we analyzed the regulatory effects of JNK1 on p21 protein accumulation in p53 null K562 cells. We found that JNK1 (wild type, WT) mediated H(2)O(2)-induced p21 protein up-regulation. Over-expression of JNK1 (WT) could elevate endogenous p21 protein level but did not affect p21 mRNA level and also prolong the p21 half-life as well as inhibited the p21 ubiquitination. These findings indicated that JNK1 could regulate cellular p21 level via inhibiting ubiquitination of p21, which provided a new insight for analyzing the regulatory effect of JNK after stress.
authors.affiliation: Jiangsu Province Key Laboratory for Molecular and Medical Biotechnology, College of Life Sciences, Nanjing Normal University, Nanjing 210097, PR China.
authors.forename: Yumei
authors.initials: Y
authors.lastname: Fan
authors.forename: Hui
authors.initials: H
authors.lastname: Chen
authors.forename: Bo
authors.initials: B
authors.lastname: Qiao
authors.forename: Ziwen
authors.initials: Z
authors.lastname: Liu
authors.forename: Lan
authors.initials: L
authors.lastname: Luo
authors.forename: Yifan
authors.initials: Y
authors.lastname: Wu
authors.forename: Zhimin
authors.initials: Z
authors.lastname: Yin
mesh_terms: D002453:Cell Cycle; D002455:Cell Division; D050759:Cyclin-Dependent Kinase Inhibitor p21 / Q000378:metabolism*; D017931:DNA Primers; D004795:Enzyme Stability; D006801:Humans; D006861:Hydrogen Peroxide / Q000494:pharmacology; D048031:JNK Mitogen-Activated Protein Kinases / Q000378:metabolism*; D020014:K562 Cells; D046988:Proteasome Endopeptidase Complex / Q000378:metabolism; D011994:Recombinant Proteins / Q000378:metabolism; D020133:Reverse Transcriptase Polymerase Chain Reaction; D025801:Ubiquitin / Q000378:metabolism*; D020741:rho GTP-Binding Proteins / Q000187:drug effects / Q000378:metabolism
chemical_list: C493956:CDKN1A protein, human; D050759:Cyclin-Dependent Kinase Inhibitor p21; D017931:DNA Primers; D011994:Recombinant Proteins; D025801:Ubiquitin; D006861:Hydrogen Peroxide; D048031:JNK Mitogen-Activated Protein Kinases; D046988:Proteasome Endopeptidase Complex; D020741:rho GTP-Binding Proteins