PROTEIN TYROSINE PHOSPHATASES - A DIVERSE FAMILY OF INTRACELLULAR AND TRANSMEMBRANE ENZYMES
PROTEIN TYROSINE PHOSPHATASES - A DIVERSE FAMILY OF INTRACELLULAR AND TRANSMEMBRANE ENZYMES
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DOI：
10.1126/science.1650499
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发表时间：
1991-07-26
期刊：
影响因子：
56.9
通讯作者：
TONKS, NK
中科院分区：
文献类型：
--
作者：
FISCHER, EH;CHARBONNEAU, H;TONKS, NK
蛋白酪氨酸磷酸酶 (PTP) 代表了以完整膜和非受体形式存在的多种酶家族。 PTP 的体外比活性比蛋白酪氨酸激酶高 10 至 1000 倍，有望有效控制细胞中磷酸酪氨酸的量。它们在体内使酪氨酰残基去磷酸化并参与信号转导和细胞周期调节。大多数跨膜形式，例如白细胞共同抗原（CD45），含有两个保守的细胞内催化结构域；但它们的外部部分变化很大。跨膜形式的结构特征表明这些受体连接的 PTP 能够转导外部信号；然而，配体仍未确定。提出了一个假设，解释磷酸酶如何与激酶协同作用以引发完整的生理反应，而不考虑靶蛋白的磷酸化状态。
Protein tyrosine phosphatases (PTPs) represent a diverse family of enzymes that exist as integral membrane and nonreceptor forms. The PTPs, with specific activities in vitro 10 to 1000 times greater than those of the protein tyrosine kinases would be expected to effectively control the amount of phosphotyrosine in the cell. They dephosphorylate tyrosyl residues in vivo and take part in signal transduction and cell cycle regulation. Most of the transmembrane forms, such as the leukocyte common antigen (CD45), contain two conserved intracellular catalytic domains; but their external segments are highly variable. The structural features of the transmembrane forms suggest that these receptor-linked PTPs are capable of transducing external signals; however, the ligands remain unidentified. A hypothesis is proposed explaining how phosphatases might act synergistically with the kinases to elicit a full physiological response, without regard to the state of phosphorylation of the target proteins.