Nutrient-dependent methylation of a membrane-associated protein of Escherichia coli.
Starvation of a mid-log-phase culture of Escherichia coli B/r for nitrogen, phosphate, or carbon resulted in methylation of a membrane-associated protein of about 43,000 daltons (P-43) in the presence of chloramphenicol and [methyl-3H]methionine. The in vivo methylation reaction occurred with a doubling time of 2 to 5 min and was followed by a slower demethylation process. Addition of the missing nutrient to a starving culture immediately prevented further methylation of P-43. P-43 methylation is not related to the methylated chemotaxis proteins because P-43 is methylated in response to a different spectrum of nutrients and because P-43 is methylated on lysine residues. The characteristics of P-43 are similar to those of a methylated protein previously described in Bacillus subtilis and B. licheniformis (R. W. Bernlohr, A. L. Saha, C. C. Young, B. R. Toth, and K. J. Golden, J. Bacteriol. 170:4113-4118, 1988; K. J. Golden and R. W. Bernlohr, Mol. Gen. Genet. 220:1-7, 1989) and are consistent with the proposal that methylation of this protein functions in nutrient sensing.
Young
C C
CC
Department of Molecular and Cell Biology, Pennsylvania State University, University Park 16802.
Alvarez
J D
JD
Bernlohr
R W
RW
D001345:Autoradiography; D002854:Chromatography, Paper; D003470:Culture Media; D004926:Escherichia coli / Q000254:growth & development* / Q000378:metabolism; D007700:Kinetics; D008565:Membrane Proteins / Q000302:isolation & purification / Q000378:metabolism*; D008715:Methionine / Q000378:metabolism; D008745:Methylation; D013997:Time Factors; D014316:Tritium
D003470:Culture Media; D008565:Membrane Proteins; D014316:Tritium; D008715:Methionine