IDENTIFICATION, CLONING, AND EXPRESSION OF A CYTOSOLIC MEGAKARYOCYTE PROTEIN-TYROSINE-PHOSPHATASE WITH SEQUENCE HOMOLOGY TO CYTOSKELETAL PROTEIN 4.1
IDENTIFICATION, CLONING, AND EXPRESSION OF A CYTOSOLIC MEGAKARYOCYTE PROTEIN-TYROSINE-PHOSPHATASE WITH SEQUENCE HOMOLOGY TO CYTOSKELETAL PROTEIN 4.1
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DOI：
10.1073/pnas.88.13.5867
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发表时间：
1991-07-01
影响因子：
11.1
通讯作者：
MAJERUS, PW
中科院分区：
文献类型：
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作者：
GU, MX;YORK, JD;MAJERUS, PW
我们分离出了编码第三种蛋白质酪氨酸磷酸酶的 cDNA。我们筛选了人巨核细胞系（MEG-01）和脐静脉内皮细胞cDNA文库，获得了3.7kb的cDNA，命名为PTPase MEG。 MEG-01 RNA 的 Northern 印迹分析检测到 3.7 kb 的转录物，表明已鉴定出全长 cDNA。 PTPase MEG cDNA 包含 926 个氨基酸的开放阅读框。该cDNA具有771个核苷酸的富含G+C的5'非翻译区，具有形成稳定的茎环结构的潜力，并且具有两个上游ATG密码子。预测的蛋白质 (M(r) = 105,910) 没有明显的跨膜区域，并包含单个蛋白质酪氨酸磷酸酶结构域（氨基酸 659-909），与之前描述的酪氨酸磷酸酶结构域有 35-40% 的同一性。当在大肠杆菌中表达时，重组磷酸酶结构域具有蛋白酪氨酸磷酸酶活性。氨基末端区域（氨基酸 31-367）与人红细胞蛋白 4.1（一种细胞骨架蛋白）的氨基末端有 45% 相同。与细胞骨架蛋白相关的蛋白酪氨酸磷酸酶的鉴定意味着细胞信号传导活性不仅存在于跨膜受体中，而且也存在于细胞骨架元件中。
We have isolated a cDNA encoding a third type of protein-tyrosine-phosphatase. We screened human megakaryoblastic cell line (MEG-01) and umbilical vein endothelial cell cDNA libraries to obtain a 3.7-kilobase cDNA designated PTPase MEG. Northern blot analysis of MEG-01 RNA detected a 3.7-kilobase transcript, suggesting that a full-length cDNA has been identified. PTPase MEG cDNA contains an open reading frame of 926 amino acids. The cDNA has a G + C-rich 5' untranslated region of 771 nucleotides that has the potential to form stable stem-loop structures and has two upstream ATG codons. The predicted protein (M(r) = 105,910) has no apparent membrane-spanning region and contains a single protein-tyrosine-phosphatase domain (amino acids 659-909) that is 35-40% identical to previously described tyrosine-phosphatase domains. The recombinant phosphatase domain possesses protein-tyrosine-phosphatase activity when expressed in Escherichia coli. The amino-terminal region (amino acids 31-367) is 45% identical to the amino terminus of human erythrocyte protein 4.1, a cytoskeletal protein. The identification of a protein-tyrosine-phosphatase that is related to cytoskeletal proteins implies that cell signaling activities reside not only in transmembrane receptors but in cytoskeletal elements as well.