Different types of modification in c-fos and its associated protein p39: modulation of DNA binding by phosphorylation.
We have studied the biosynthesis and biochemical properties of the c-fos gene product and its associated protein (p39) in growth factor-stimulated fibroblasts. c-fos is a markedly acidic protein that is extensively post-translationally modified by phosphorylation and another type of modification not changing its relative molecular mass (Mr). More than 10 different forms of c-fos protein can be identified by two-dimensional gel analysis. In c-fos-transformed cells, however, most of the highly modified forms are missing. The affinity for DNA of less phosphorylated c-fos-protein complexes is higher than that of the highly modified ones. The transforming potential of c-fos protein and its affinity for DNA thus seems to be inversely correlated with the extent of its phosphorylation. In contrast to c-fos, p39 is a basic protein that is rendered even more basic by post-translational modification. Two other forms of p39 differing in specific domains of the protein (p41 and p43) were also found to be complexed with c-fos.
Müller
R
R
European Molecular Biology Laboratory, Heidelberg, Fed. Rep. of Germany.
Bravo
R
R
Müller
D
D
Kurz
C
C
Renz
M
M
D000818:Animals; D000936:Antigen-Antibody Complex / Q000032:analysis; D002460:Cell Line; D004247:DNA / Q000378:metabolism; D004268:DNA-Binding Proteins / Q000096:biosynthesis / Q000378:metabolism; D015180:Electrophoresis, Gel, Two-Dimensional; D051379:Mice; D010449:Peptide Mapping; D010750:Phosphoproteins / Q000096:biosynthesis; D010766:Phosphorylation; D011233:Precipitin Tests; D011487:Protein Conformation; D011499:Protein Processing, Post-Translational; D011518:Proto-Oncogene Proteins / Q000096:biosynthesis*; D016760:Proto-Oncogene Proteins c-fos; D016755:Proto-Oncogene Proteins c-jun
D000936:Antigen-Antibody Complex; D004268:DNA-Binding Proteins; D010750:Phosphoproteins; D011518:Proto-Oncogene Proteins; D016760:Proto-Oncogene Proteins c-fos; D016755:Proto-Oncogene Proteins c-jun; D004247:DNA