Acylation of monocyte and glomerular mesangial cell proteins. Myristyl acylation of the interleukin 1 precursors.
Acylation of cellular proteins with the fatty acids myristate or palmitate represents an important mechanism for the co- or posttranslational modification of proteins. Lipid A, the biologically active component of bacterial endotoxin, exerts a number of biochemical effects on responsive cell types. Evidence is presented that lipid A stimulates the synthesis and subsequent myristyl acylation of intracellular monocyte and glomerular mesangial cell proteins. Two of the myristylated monocyte proteins were identified by specific immunoprecipitation as the 33-kD IL 1 alpha and beta precursors; a similar myristylated protein was found in mesangial cells. The 17-kD secretory form of monocyte IL 1 beta did not contain covalently linked myristate. Myristyl acylation of the IL 1 precursor proteins may facilitate the processing or membrane localization of these proteins, which lack characteristic hydrophobic signal sequences. The acylated 33-kD IL 1 alpha may remain preferentially associated with the membrane in an active form, whereas limited proteolysis may convert the biologically inactive IL 1 beta precursor into the extracellular, nonacylated, active 17-kD protein.
Bursten
S L
SL
Medical Service, Seattle Veterans Administration Medical Center-University of Washington 98108.
Locksley
R M
RM
Ryan
J L
JL
Lovett
D H
DH
D000215:Acylation; D000818:Animals; D005920:Glomerular Mesangium / Q000378:metabolism*; D006863:Hydrogen-Ion Concentration; D007375:Interleukin-1 / Q000378:metabolism*; D008050:Lipid A / Q000494:pharmacology; D008297:Male; D008715:Methionine / Q000378:metabolism; D008970:Molecular Weight; D009000:Monocytes / Q000378:metabolism*; D019814:Myristic Acid; D009227:Myristic Acids / Q000378:metabolism*; D011498:Protein Precursors / Q000378:metabolism*; D051381:Rats; D011919:Rats, Inbred Strains
D007375:Interleukin-1; D008050:Lipid A; D009227:Myristic Acids; D011498:Protein Precursors; C043830:interleukin 1 precursor; D019814:Myristic Acid; D008715:Methionine