title: Multiple functions of p21 in cell cycle, apoptosis and transcriptional regulation after DNA damage.
abstract: An appropriate control over cell cycle progression depends on many factors. Cyclin-dependent kinase (CDK) inhibitor p21 (also known as p21(WAF1/Cip1)) is one of these factors that promote cell cycle arrest in response to a variety of stimuli. The inhibitory effect of P21 on cell cycle progression correlates with its nuclear localization. P21 can be induced by both p53-dependent and p53-independent mechanisms. Some other important functions attributed to p21 include transcriptional regulation, modulation or inhibition of apoptosis. These functions are largely dependent on direct p21/protein interactions and also on p21 subcellular localizations. In addition, p21 can play a role in DNA repair by interacting with proliferating cell nuclear antigen (PCNA). In this review, we will focus on the multiple functions of p21 in cell cycle regulation, apoptosis and gene transcription after DNA damage and briefly discuss the pathways and factors that have critical roles in p21 expression and activity.
authors.affiliation: Immunology Research Center, Tabriz University of Medical Sciences, Tabriz, Iran; Department of Clinical Biochemistry and Laboratory Medicine, Faculty of Medicine, Tabriz University of Medical Sciences, Tabriz, Iran; Student Research Committee, Tabriz University of Medical Sciences, Tabriz, Iran.
authors.forename: Ansar
authors.initials: A
authors.lastname: Karimian
authors.affiliation: Department of Clinical Biochemistry and Laboratory Medicine, Faculty of Medicine, Tabriz University of Medical Sciences, Tabriz, Iran; Student Research Committee, Tabriz University of Medical Sciences, Tabriz, Iran.
authors.forename: Yasin
authors.initials: Y
authors.lastname: Ahmadi
authors.affiliation: Department of Clinical Biochemistry and Laboratory Medicine, Faculty of Medicine, Tabriz University of Medical Sciences, Tabriz, Iran; Student Research Committee, Tabriz University of Medical Sciences, Tabriz, Iran; Drug Applied Research Center, Tabriz University of Medical Sciences, Tabriz, Iran. Electronic address: yousefib@tbzmed.ac.ir.
authors.forename: Bahman
authors.initials: B
authors.lastname: Yousefi
mesh_terms: D000818:Animals; D017209:Apoptosis / Q000235:genetics*; D002453:Cell Cycle / Q000235:genetics*; D050759:Cyclin-Dependent Kinase Inhibitor p21 / Q000378:metabolism*; D003593:Cytoplasm / Q000378:metabolism; D004249:DNA Damage; D006801:Humans; D014158:Transcription, Genetic / Q000235:genetics*
chemical_list: D050759:Cyclin-Dependent Kinase Inhibitor p21
keywords: Apoptosis; Cell cycle; DNA damage; p21