title: Expression of RB C pocket fragments in HSF induces delayed cell cycle progression and sensitizes to apoptosis upon cellular stresses.
abstract: The retinoblastoma protein (RB) plays an important role in growth suppression through the formation of multiple protein complexes with its target proteins using A/B and C pockets. Even though the A/B and C pockets co-operate for growth suppression, the function of RB in growth arrest is inhibited by the coexpression of RB C fragments with full length RB in the absence of p53, which implies that C pocket fragments are likely to act as a dominant-negative inhibitor of RB function. In contrast, the loss of the RB functions in the presence of p53 triggers a cell cycle arrest or apoptosis by p53-dependent pathways. Thus, it still remains to be elucidated whether the expression of RB C pocket fragments in the presence of p53 induces delayed cell cycle progression and sensitizes cells to apoptosis through p53-dependent pathways. Our results show that the expression of RB C pocket fragments not only induces delayed cell cycle progression, which is mediated by the down-regulation of cyclin A, cyclin E, and E2F-1, but also sensitizes cells to apoptosis through p53-dependent pathways.
authors.affiliation: Department of Microbiology, School of Medicine, Keimyung University, Taegu, Republic of Korea.
authors.forename: Junah
authors.initials: J
authors.lastname: Chung
authors.forename: Jae-We
authors.initials: JW
authors.lastname: Cho
authors.forename: Won-Ki
authors.initials: WK
authors.lastname: Baek
authors.forename: Seong-Il
authors.initials: SI
authors.lastname: Suh
authors.forename: Taeg Kyu
authors.initials: TK
authors.lastname: Kwon
authors.forename: Jong-Wook
authors.initials: JW
authors.lastname: Park
authors.forename: Min-Ho
authors.initials: MH
authors.lastname: Suh
mesh_terms: D017209:Apoptosis / Q000502:physiology*; D005347:Fibroblasts / Q000166:cytology* / Q000502:physiology; D016193:G1 Phase / Q000502:physiology; D015870:Gene Expression / Q000502:physiology; D006801:Humans; D010446:Peptide Fragments / Q000235:genetics; D016160:Retinoblastoma Protein / Q000235:genetics* / Q000378:metabolism*; D015398:Signal Transduction / Q000502:physiology; D012867:Skin / Q000166:cytology; D014162:Transfection; D016159:Tumor Suppressor Protein p53 / Q000502:physiology
chemical_list: D010446:Peptide Fragments; D016160:Retinoblastoma Protein; D016159:Tumor Suppressor Protein p53