Induction of leucine aminopeptidase by interferon-gamma. Identification by protein microsequencing after purification by preparative two-dimensional gel electrophoresis.
The protein previously called "Mr approximately 50/pI approximately 6.9," which we observed to be induced by the immunoregulatory cytokine interferon (IFN)-gamma in human fibroblasts, was purified from a total cell lysate by preparative two-dimensional gel electrophoresis and identified by partial amino-terminal sequencing as leucine aminopeptidase (LAP), a 53-kDa cytosolic exopeptidase. Induction of LAP protein by IFN-gamma, confirmed by immunoblotting with an antiserum raised against bovine lens LAP, is a consequence of induction of LAP mRNA and occurs in all four human cell lines examined: HS153 fibroblasts, ACHN renal carcinoma, A549 lung carcinoma, and A375 melanoma. Induction of LAP mRNA is a secondary response to IFN-gamma, blocked by inhibition of protein synthesis with cycloheximide.
Harris
C A
CA
Cancer Research Institute, University of California, San Francisco 94143.
Hunte
B
B
Krauss
M R
MR
Taylor
A
A
Epstein
L B
LB
D000595:Amino Acid Sequence; D015152:Blotting, Northern; D015153:Blotting, Western; D003513:Cycloheximide / Q000494:pharmacology; D004247:DNA / Q000235:genetics; D015342:DNA Probes; D015180:Electrophoresis, Gel, Two-Dimensional; D006801:Humans; D007371:Interferon-gamma / Q000494:pharmacology*; D007700:Kinetics; D007931:Leucyl Aminopeptidase / Q000096:biosynthesis* / Q000302:isolation & purification; D008969:Molecular Sequence Data; D011500:Protein Synthesis Inhibitors / Q000494:pharmacology; D012333:RNA, Messenger / Q000096:biosynthesis; D014407:Tumor Cells, Cultured
D015342:DNA Probes; D011500:Protein Synthesis Inhibitors; D012333:RNA, Messenger; D007371:Interferon-gamma; D004247:DNA; D003513:Cycloheximide; D007931:Leucyl Aminopeptidase