The biology of p21 Waf1/Cip1 - review paper

p21WAF1/Cip1 belongs to the Cip/Kip family of cyclin kinase inhibitors (CKI) (p21Waf1/Cip1, p27Kip1, p57Kip1). p21Waf1/Cip1 was first described as a potent and universal inhibitor of cyclin-dependent kinases (Cdks). Two forms of functionally active p21 has been localized and described: a nuclear and a cytoplasmic forms. In this paper the structures of p21 has been described and as well as it functional biology in terms of differentiation, proliferation and apoptotic activities. The upregulation of p21 by p53-dependent and p53-independent mechanisms is also described.peer-reviewe