Growth-related expression of a 72,000 molecular weight poly(A)+ mRNA binding protein.
In this communication, we have studied a 72,000 mol w (p72) host protein which reacts with a mouse monoclonal antibody (PAb6) directed against antigenic determinants on the Simian virus 40 (SV40) large T antigen protein that map 5' of 0.42 map units on the viral genome. The p72 protein is an abundant basic (pI greater than 7) cytoplasmic protein found in both SV40-transformed and untransformed parental cells and in cell lines derived from normal human and tumor tissue. By two-dimensional gel analysis and Western blot analysis the p72 protein identified by PAb6 is indistinguishable from the 72,000 mol w protein PABP associated with the poly(A)+ tract of cytoplasmic messenger RNA molecules. In normal human peripheral blood mononuclear cells stimulated to proliferate with the T-cell-specific mitogenic lectin phytohemagglutinin the synthesis and cytoplasmic accumulation of p72 occurs very early during the G0----G1-phase transition. The p72 protein is also expressed in proliferating and differentiated human promyelocytic HL60 cells indicating that the expression of this protein is not strictly limited to cycling cells.
Ullrich
S J
SJ
Laboratory of Cell Biology, National Institutes of Health, Bethesda, Maryland 20892.
Appella
E
E
Mercer
W E
WE
D000818:Animals; D000911:Antibodies, Monoclonal / Q000276:immunology; D000952:Antigens, Polyomavirus Transforming / Q000276:immunology; D015153:Blotting, Western; D002352:Carrier Proteins / Q000032:analysis / Q000096:biosynthesis* / Q000276:immunology; D002455:Cell Division; D002460:Cell Line; D002461:Cell Line, Transformed; D002478:Cells, Cultured; D003429:Cross Reactions; D004591:Electrophoresis, Polyacrylamide Gel; D000939:Epitopes / Q000276:immunology; D006801:Humans; D007124:Immunoenzyme Techniques; D007150:Immunohistochemistry; D007399:Interphase; D007700:Kinetics; D008213:Lymphocyte Activation; D011061:Poly A / Q000378:metabolism*; D039102:Poly(A)-Binding Proteins; D011233:Precipitin Tests; D012333:RNA, Messenger / Q000378:metabolism*; D013601:T-Lymphocytes / Q000166:cytology; D014407:Tumor Cells, Cultured
D000911:Antibodies, Monoclonal; D000952:Antigens, Polyomavirus Transforming; D002352:Carrier Proteins; D000939:Epitopes; D039102:Poly(A)-Binding Proteins; D012333:RNA, Messenger; D011061:Poly A