CLONING AND CHARACTERIZATION OF A NOVEL CDNA THAT IS IFN-GAMMA-INDUCED IN MOUSE PERITONEAL-MACROPHAGES AND ENCODES A PUTATIVE GTP-BINDING PROTEIN
CLONING AND CHARACTERIZATION OF A NOVEL CDNA THAT IS IFN-GAMMA-INDUCED IN MOUSE PERITONEAL-MACROPHAGES AND ENCODES A PUTATIVE GTP-BINDING PROTEIN
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DOI：
10.1002/jlb.57.3.477
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发表时间：
1995-03-01
影响因子：
5.5
通讯作者：
ZWILLING, BS
中科院分区：
文献类型：
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作者：
LAFUSE, WP;BROWN, D;ZWILLING, BS
为了鉴定小鼠腹膜巨噬细胞中被ifn - γ激活的基因，我们创建了一个ifn - γ诱导基因的cDNA减法文库，我们从这个减法文库中分离出一种新的cDNA，称为Mg21，其mRNA在未受刺激的小鼠腹膜巨噬细胞中不存在，并且在加入ifn - γ后4小时内被诱导到高水平。在环己亚胺存在的情况下，ifn - γ诱导Mg21 mRNA的表达，表明Mg21 mRNA的表达不需要蛋白质合成。LPS也能诱导少量Mg21 mRNA表达，但IL-2、IL-4、IL-10或tnf - α均不能诱导。Mg21的DNA序列为1617个核苷酸，包含一个开放阅读框，编码一个415个氨基酸的蛋白质，预测分子量为47,106 Da。预测的氨基酸序列缺少信号序列或跨膜片段，表明该蛋白是胞内蛋白。计算机检索GenBank和EMBL数据库表明，该cDNA克隆是独特的，但与IRG-47有57%的序列同源性，IRG-47是由ifn - γ诱导的小鼠B前和B淋巴细胞细胞系基因，IRG-47编码胞内蛋白，该蛋白含有gtp结合蛋白中存在的三个保守蛋白基序。对Mg21蛋白序列的分析表明，这三个保守的蛋白基序也存在于Mg21中。
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 done, 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.