Involvement of retinoblastoma protein in p27Kip1-induced apoptosis.
p27Kip1, a cyclin-dependent kinase (CDK) inhibitor, plays a critical role in cell cycle regulation. Expression of p27Kip1 is shown to increase during apoptosis in mammalian cells. Here, to directly address the role of p27Kip1 in apoptosis, p27Kip1 is overexpressed in human SK-Hep1 hepatoma cells. This leads to apoptotic cell death and this reduces protein, but not mRNA, levels of the retinoblastoma (Rb). Consistently, accumulation of Rb protein blocks p27Kip1-mediated apoptosis. These studies demonstrate an involvement of Rb in the apoptotic cell death which is induced by overexpression of p27Kip1.
Oh
S
S
Institute for Molecular Biology and Genetics, Department of Microbiology, Seoul National University, South Korea.
Kim
T K
TK
Hwang
D S
DS
Yim
J
J
D017209:Apoptosis; D015153:Blotting, Western; D018797:Cell Cycle Proteins; D050760:Cyclin-Dependent Kinase Inhibitor p27; D018844:Cyclin-Dependent Kinases / Q000037:antagonists & inhibitors; D004247:DNA / Q000032:analysis / Q000235:genetics; D053938:DNA Fragmentation; D015536:Down-Regulation; D015870:Gene Expression; D006801:Humans; D008113:Liver Neoplasms / Q000235:genetics / Q000378:metabolism / Q000473:pathology; D008869:Microtubule-Associated Proteins / Q000037:antagonists & inhibitors* / Q000235:genetics / Q000378:metabolism*; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D016160:Retinoblastoma Protein / Q000235:genetics / Q000378:metabolism*; D014162:Transfection; D014407:Tumor Cells, Cultured; D016159:Tumor Suppressor Protein p53 / Q000235:genetics / Q000378:metabolism; D025521:Tumor Suppressor Proteins
D018797:Cell Cycle Proteins; D008869:Microtubule-Associated Proteins; D012333:RNA, Messenger; D016160:Retinoblastoma Protein; D016159:Tumor Suppressor Protein p53; D025521:Tumor Suppressor Proteins; D050760:Cyclin-Dependent Kinase Inhibitor p27; D004247:DNA; D018844:Cyclin-Dependent Kinases