The Retinoblastoma Protein and Cell-Cycle Control：（视网膜母细胞瘤蛋白和细胞循环控制）.pdfVIP

Cell,Vol. 81,323-330, May5, 1995,Copyright© 1995by Cell Press The Retinoblastoma Protein Review and Cell Cycle Control Robert A. Weinberg The schedule of pRB phosphorylation leads to a simple Whitehead Institute for Biomedical Research and attractive functional model that is still largely unproven. Massachusetts Institute of Technology A cell that has proceeded through most of G1 encounters Cambridge, Massachusetts 02142 the R point gate held shut by its guardian, pRB. Should conditions be propitious for advance into the remainder of the cell cycle, pRB will undergo phosphorylation and pRB, the product of the retinoblastoma tumor suppressor attendant functional inactivation, causing it to open the gene, operates in the midst of the cell cycle clock appara- gate and to permit the cell to proceed into late G1. Cells tus. Its main role is to act as a signal transducer connecting that lack pRB function for a variety of reasons will proceed the cell cycle clock with the transcriptional machinery. In blithely into late G1 without undergoing the control nor- this role, pRB allows the clock to control the expression mally imposed by pRB and, by extension, the upstream of banks of genes that mediate advance of the cell through influences that regulate its phosphorylation. These up- a critical phase of its growth cycle. Loss of pRB function stream influences include growth-promoting signals such deprives the clock and thus the cell of an important mecha-