Characterization of cytoplasmic and nuclear polypeptides induced by interferon-gamma in a murine pre-B cell leukemia.
The effects of interferon-gamma (IFN-gamma) on protein synthesis of a pre-B cell leukemia, L1210, have been studied by two-dimensional gel electrophoresis. In total cell extracts, at least ten proteins were induced de novo, or increased in their expression, after an 18-h IFN-gamma treatment, whereas in the nuclear extracts eight proteins were specifically induced. Of these, increased synthesis of a 40-kDa/pI 5.9 cytoplasmic protein was the most prominent and reproducible. Most of these proteins appear to be specific for a defined step of differentiation, since they are not found in other B cell leukemias upon IFN-gamma treatment. Others appear to be tissue specific, since they are not induced in fibroblasts nor in T cells. In addition, synthesis of some of the induced proteins appeared to require rapid transcription of new mRNA, because actinomycin D markedly inhibited their formation when added immediately before IFN-gamma. In keeping with this finding, in vitro translation of mRNA from IFN-gamma-treated L1210 cells into a rabbit reticulocyte lysate system, followed by analysis of the labeled proteins by two-dimensional gel electrophoresis, revealed the appearance of at least seven proteins. Taken as a whole, these results demonstrate that in leukemic pre-B cells IFN-gamma induces the transcriptional activation of genes coding for cytoplasmic and nuclear proteins, some of which could be employed as specific cell activation markers.
Franco
A
A
Institute of Microbiology, University of Torino, Italy.
Fizzotti
M
M
Gariglio
M
M
Gribaudo
G
G
Cavallo
G
G
Landolfo
S
S
D000818:Animals; D000954:Antigens, Surface / Q000032:analysis; D003593:Cytoplasm / Q000378:metabolism; D003609:Dactinomycin / Q000494:pharmacology; D015180:Electrophoresis, Gel, Two-Dimensional; D007370:Interferon Type I / Q000494:pharmacology; D007371:Interferon-gamma / Q000494:pharmacology*; D007526:Isoelectric Point; D051379:Mice; D008970:Molecular Weight; D009363:Neoplasm Proteins / Q000378:metabolism*; D009687:Nuclear Proteins / Q000378:metabolism*; D015452:Precursor B-Cell Lymphoblastic Leukemia-Lymphoma / Q000503:physiopathology*; D014176:Protein Biosynthesis; D012333:RNA, Messenger / Q000235:genetics; D012334:RNA, Neoplasm / Q000235:genetics; D011994:Recombinant Proteins
D000954:Antigens, Surface; D007370:Interferon Type I; D009363:Neoplasm Proteins; D009687:Nuclear Proteins; D012333:RNA, Messenger; D012334:RNA, Neoplasm; D011994:Recombinant Proteins; D003609:Dactinomycin; D007371:Interferon-gamma