A key difference among the three structurally similar pRB family members is that only pRB is a tumor suppressor. Identification of distinctive functional differences between pRB and p107/p130 therefore holds promise for a better understanding of the tumor suppression mechanisms of pRB. Enigmatically, pRB and p107 have been shown to have indistinguishable growth suppression activities when studied in the pRB-deficient Saos-2 cell system. In this study, we discovered that, when expressed at physiologically relevant levels, pRB and p107 had distinctive effects in causing growth suppression. pRB induced cellular p130 levels while p107 repressed them. p107, but not pRB, blocked cells inside S phase in addition to G1 arrest. In contrast, no qualitative differences were identified in their abilities to repress the expression of a set of suspected pRB/E2F repression target genes. These results indicate that pRB and p107 possess different growth suppression effects, despite the fact that they have similar E2F repression effects.
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http://dx.doi.org/10.1038/sj.onc.1203722 | DOI Listing |
Differentiation
June 2024
Department of Biochemistry and Cell Biology, Stony Brook University, Stony Brook, NY, 11794, USA. Electronic address:
The acquisition of the post-mitotic state is crucial for the execution of many terminally differentiated cell behaviors during organismal development. However, the mechanisms that maintain the post-mitotic state in this context remain poorly understood. To gain insight into these mechanisms, we used the genetically and visually accessible model of C.
View Article and Find Full Text PDFbioRxiv
February 2024
Department of Biochemistry and Cell Biology, Stony Brook University, Stony Brook, NY 11794, USA.
The acquisition of the post-mitotic state is crucial for the execution of many terminally differentiated cell behaviors during organismal development. However, the mechanisms that maintain the post-mitotic state in this context remain poorly understood. To gain insight into these mechanisms, we used the genetically and visually accessible model of anchor cell (AC) invasion into the vulval epithelium.
View Article and Find Full Text PDFJ Virol
February 2023
Department of Microbiology and Immunology, Louisiana State University Health Sciences Center-Shreveport, Shreveport, Louisiana, USA.
Coinfection of human papillomavirus (HPV) and Epstein-Barr virus (EBV) has been detected in oropharyngeal squamous cell carcinoma. Although HPV and EBV replicate in differentiated epithelial cells, we previously reported that HPV epithelial immortalization reduces EBV replication within organotypic raft culture and that the HPV16 oncoprotein E7 was sufficient to inhibit EBV replication. A well-established function of HPV E7 is the degradation of the retinoblastoma (Rb) family of pocket proteins (pRb, p107, and p130).
View Article and Find Full Text PDFFront Endocrinol (Lausanne)
June 2022
Institute of Biomedicine, Research Centre for Integrative Physiology and Pharmacology, University of Turku, Turku, Finland.
The retinoblastoma (RB) protein family members (pRB, p107 and p130) are key regulators of cell cycle progression, but also play crucial roles in apoptosis, and stem cell self-renewal and differentiation. RB proteins exert their effects through binding to E2F transcription factors, which are essential developmental and physiological regulators of tissue and organ homeostasis. According to the canonical view, phosphorylation of RB results in release of E2Fs and induction of genes needed for progress of the cell cycle.
View Article and Find Full Text PDFCancers (Basel)
April 2022
Institute of Human Genetics, University Hospital Essen, University of Duisburg-Essen, 45147 Essen, Germany.
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