title: Cloning and characterization of a novel cDNA that is IFN-gamma-induced in mouse peritoneal macrophages and encodes a putative GTP-binding protein.
abstract: Macrophage activation by IFN-gamma results in a cascade of gene expression. To identify genes activated in mouse peritoneal macrophages by IFN-gamma, we created a cDNA subtraction library of IFN-gamma-induced genes. We have isolated from this subtraction library a novel cDNA clone, called Mg21, whose mRNA is absent in unstimulated mouse peritoneal macrophages and is induced to high levels within 4 h following the addition of IFN-gamma. Induction of Mg21 mRNA by IFN-gamma occurred in the presence of cycloheximide, indicating that expression of Mg21 mRNA does not require protein synthesis. A small amount of Mg21 mRNA was also induced by LPS, but not by IL-2, IL-4, IL-10, or TNF-alpha. The DNA sequence of Mg21 is 1617 nucleotides and contains an open reading frame that codes for a protein of 415 amino acids with a predicted molecular weight of 47,106 Da. The predicted amino acid sequence lacks a signal sequence or transmembrane segments, indicating that the protein is an intracellular protein. Computer search of the GenBank and EMBL databases indicates that this cDNA clone is unique but has 57% sequence identity with IRG-47, which is a mouse gene induced by IFN-gamma in pre-B and B lymphocyte cell lines. IRG-47 encodes an intracellular protein that contains three conserved protein motifs present in GTP-binding proteins. Analysis of the protein sequence of Mg21 showed that these three conserved protein motifs are also present in Mg21.
authors.affiliation: Department of Medical Microbiology and Immunology, Ohio State University, Columbus 43210.
authors.forename: W P
authors.initials: WP
authors.lastname: Lafuse
authors.forename: D
authors.initials: D
authors.lastname: Brown
authors.forename: L
authors.initials: L
authors.lastname: Castle
authors.forename: B S
authors.initials: BS
authors.lastname: Zwilling
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D003001:Cloning, Molecular; D016384:Consensus Sequence; D016207:Cytokines / Q000494:pharmacology; D018076:DNA, Complementary / Q000235:genetics; D019204:GTP-Binding Proteins / Q000235:genetics*; D005786:Gene Expression Regulation / Q000187:drug effects; D007371:Interferon-gamma / Q000494:pharmacology; D008070:Lipopolysaccharides / Q000494:pharmacology; D008297:Male; D051379:Mice; D008807:Mice, Inbred BALB C; D008969:Molecular Sequence Data; D020559:Monomeric GTP-Binding Proteins; D005810:Multigene Family; D012333:RNA, Messenger / Q000235:genetics; D000076106:SAM Domain and HD Domain-Containing Protein 1; D016415:Sequence Alignment
chemical_list: D016207:Cytokines; D018076:DNA, Complementary; D008070:Lipopolysaccharides; D012333:RNA, Messenger; C092499:Tgtp protein, mouse; D007371:Interferon-gamma; D000076106:SAM Domain and HD Domain-Containing Protein 1; C484281:Samhd1 protein, mouse; D019204:GTP-Binding Proteins; D020559:Monomeric GTP-Binding Proteins