Induction of hepatic synthesis of serum amyloid A protein and actin.
Major changes in the mRNA population of murine liver occur after administration of bacterial lipopolysaccharide, an agent that causes increases in the concentrations of acute-phase serum proteins. The mRNA for one of these, serum amyloid A, is increased at least 500-fold compared to the normal level. It becomes one of the most abundant hepatic mRNAs, and serum amyloid A synthesis comprises about 2.5% of total hepatic protein synthesis in the acute-phase response. Its synthesis is tissue-specific in that amyloid A mRNA was not detected in the kidney, an important site of amyloid fibril accumulation. The protein synthesized in largest amount by acute-phase liver tissue in culture is cytoplasmic actin. Its relative rate of synthesis is increased about 5-fold compared to the normal tissue; that of serum albumin is decreased to about one-third of its normal rate. The concentration of mRNA for serum albumin is decreased by a similar amount. Starting with induced liver RNA, we have constructed a recombinant plasmid containing most of the DNA sequence encoding the serum amyloid A polypeptide.
D000199:Actins / Q000096:biosynthesis*; D000418:Albumins / Q000096:biosynthesis; D000682:Amyloid / Q000096:biosynthesis*; D000818:Animals; D002474:Cell-Free System; D005786:Gene Expression Regulation; D008070:Lipopolysaccharides / Q000494:pharmacology; D008099:Liver / Q000378:metabolism*; D008297:Male; D051379:Mice; D011498:Protein Precursors / Q000378:metabolism; D012333:RNA, Messenger / Q000378:metabolism; D000685:Serum Amyloid A Protein / Q000096:biosynthesis* / Q000235:genetics
D000199:Actins; D000418:Albumins; D000682:Amyloid; D008070:Lipopolysaccharides; D011498:Protein Precursors; D012333:RNA, Messenger; D000685:Serum Amyloid A Protein