Cloning of the gp49B gene of the immunoglobulin superfamily and demonstration that one of its two products is an early-expressed mast cell surface protein originally described as gp49.
Cloning of the gp49B gene of the immunoglobulin superfamily and demonstration that one of its two products is an early-expressed mast cell surface protein originally described as gp49.
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DOI：
10.1016/s0021-9258(17)37207-1
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发表时间：
1994-03
期刊：
影响因子：
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通讯作者：
M. Castells;X. Wu;J. Arm;K. Austen;H. Katz
中科院分区：
文献类型：
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作者：
M. Castells;X. Wu;J. Arm;K. Austen;H. Katz
gp49最初被定义为一种49-kDa的表面糖蛋白，优先表达于小鼠白细胞介素-3依赖性骨髓来源的肥大细胞，这些肥大细胞是未成熟的祖细胞。先前克隆的cDNA （gp49A）表明gp49是免疫球蛋白（Ig）超家族的成员，基因组DNA分析表明两个基因可能编码gp49家族。我们现在已经鉴定了一个5.6千碱基对的基因gp49B，它编码两个新的gp49cdna， gp49B1和gp49B2。除了gp49B2缺少编码预测跨膜结构域的外显子6外，这两个cdna是相同的。与gp49A相比，gp49B1和gp49B2在其C端有32个额外的氨基酸，其中包含在几个信号转导Ig超家族成员中发现的抗原受体同源性1基序的6个一致氨基酸中的4个。当用gp49B1或gp49B2 cDNA转染COS-7细胞时，只有gp49B1转染物与最初定义gp49的B23.1单克隆抗体结合。逆转录-聚合酶链反应分析证实两个转录本均有表达，表明gp49B2转录本的产物未插入质膜。因此，克隆gp49B基因建立了gp49基因之一的组织结构，并提供了该基因转录本交替剪接的证据。
gp49 was originally defined as a 49-kDa surface glycoprotein preferentially expressed on mouse interleukin-3-dependent, bone marrow-derived mast cells, which are immature progenitor cells. A previously cloned cDNA (gp49A) indicated that gp49 was a member of the immunoglobulin (Ig) superfamily, and genomic DNA analysis indicated that two genes might encode a gp49 family. We have now characterized a 5.6-kilobase pair gene, gp49B, that encodes two novel gp49 cDNAs, gp49B1 and gp49B2. The two cDNAs are identical except that gp49B2 is missing exon 6, which encodes a predicted transmembrane domain. In contrast to gp49A, gp49B1 and gp49B2 have 32 additional amino acids at their C termini containing 4 of the 6 consensus amino acids of the antigen receptor homology 1 motif found on several signal-transducing members of the Ig superfamily. When COS-7 cells were transfected with either the gp49B1 or gp49B2 cDNA, only the gp49B1 transfectants bound the B23.1 monoclonal antibody that originally defined gp49. Reverse transcriptase-polymerase chain reaction analysis of the transfectants established that both transcripts were expressed, suggesting that the product of the gp49B2 transcript was not inserted in the plasma membrane. Thus, cloning of the gp49B gene has established the organization of one of the gp49 genes and provided evidence of alternate splicing of transcripts from that gene.