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The Rb2/p130 gene product is a nuclear protein whose phosphorylation is cycle regulated
Author(s) -
Baldi Alfonso,
De Luca Antonio,
Claudio Pier Paolo,
Baldi Feliciano,
Giordano Giovan Giacomo,
Tommasino Massimo,
Paggi Marco Giorgio,
Giordano Antonio
Publication year - 1995
Publication title -
journal of cellular biochemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.028
H-Index - 165
eISSN - 1097-4644
pISSN - 0730-2312
DOI - 10.1002/jcb.240590311
Subject(s) - phosphorylation , protein phosphorylation , gene , microbiology and biotechnology , gene product , chemistry , nuclear protein , product (mathematics) , gps2 , biology , gene expression , biochemistry , hspa2 , transcription factor , mathematics , peptide sequence , protein kinase a , geometry
The Rb2/p130 protein has been shown to have a high sequence homology with the retinoblastoma gene product (pRb), one of the most well‐characterized tumor suppressor genes, and with pRb‐related p107, especially in their conserved pocket domains, which display a primary role in the function of these proteins. In this study, we report on the biochemical and immunocytochemical characterization of the Rb2/p130 protein, using a polyclonal antibody developed against its “spacer” region included in the pocket domain of the whole protein. We show that pRb/p130 is a phosphoprotein located at the nuclear level and that its phosphorylation pathway can be dramatically reduced by phosphatase treatment. Moreover pRb/p130, with p107, with p107, is one of the major targets of the E1A viral oncoprotein‐associated kinase activity, showing a phosphorylation pattern which is modulated during the cell cycle, reaching a peak of activation at the onset of S‐phase. © 1995 Wiley‐Liss, Inc.