THE LEUKOCYTE COMMON ANTIGEN (CD45) - A PUTATIVE RECEPTOR-LINKED PROTEIN TYROSINE PHOSPHATASE
THE LEUKOCYTE COMMON ANTIGEN (CD45) - A PUTATIVE RECEPTOR-LINKED PROTEIN TYROSINE PHOSPHATASE
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DOI：
10.1073/pnas.85.19.7182
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发表时间：
1988-10-01
影响因子：
11.1
通讯作者：
FISCHER, EH
中科院分区：
文献类型：
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作者：
CHARBONNEAU, H;TONKS, NK;FISCHER, EH
一种主要的蛋白酪氨酸磷酸酶（PTP 1B）已被分离出来，在基本上均匀的形式从可溶性和颗粒级分的人胎盘。出乎意料的是，部分氨基酸序列显示没有同源性的蛋白质Ser/Thr磷酸酶推导的cDNA克隆的一级结构。然而，该序列与白细胞共同抗原（CD 45）的串联C末端同源结构域惊人地相似。一个157个残基的片段的PTA 1B显示40%和33%的序列同一性，从人CD 45的胞质结构域I和II的相应区域。在调节蛋白家族如蛋白激酶和环核苷酸磷酸二酯酶的催化结构域中已经观察到类似程度的同一性。在此基础上，提出CD 45家族具有蛋白酪氨酸磷酸酶活性，可能代表一组参与信号转导的细胞表面受体。这表明，信号转导机制的剧目可能包括细胞内蛋白酪氨酸磷酸酶的直接控制，提供了与这些蛋白酪氨酸激酶的调节平衡的可能性，这些蛋白酪氨酸激酶在膜的内表面的行为。
A major protein tyrosine phosphatase (PTPase 1B) has been isolated in essentially homogeneous form from the soluble and particulate fractions of human placenta. Unexpectedly, partial amino acid sequences displayed no homology with the primary structures of the protein Ser/Thr phosphatases deduced from cDNA clones. However, the sequence is strikingly similar to the tandem C-terminal homologous domains of the leukocyte common antigen (CD45). A 157-residue segment of PTPase 1B displayed 40% and 33% sequence identity with corresponding regions from cytoplasmic domains I and II of human CD45. Similar degrees of identity have been observed among the catalytic domains of families of regulatory proteins such as protein kinases and cyclic nucleotide phosphodiesterases. On this basis, it is proposed that the CD45 family has protein tyrosine phosphatase activity and may represent a set of cell-surface receptors involved in signal transduction. This suggests that the repertoire of signal transduction mechanisms may include the direct control of an intracellular protein tyrosine phosphatase, offering the possibility of a regulatory balance with those protein tyrosine kinases that act at the internal surface of the membrane.