蛋白酪氨酸激酶（PTK）是一大类酶，调节许多细胞过程。其广泛信号作用的关键在于它们可调节的底物特异性和调节机制，允许每个酶响应适当的调节信号并磷酸化正确的生理蛋白底物。因此，除了一般的PTK催化平台外，每个PTK还获得了独特的结构基序，赋予其独特的催化和调节特性组合。了解这些特性的结构基础对于了解和操作正常细胞和癌细胞中基于PTK的信号网络至关重要。C端Src激酶（Csk）及其同源物Csk同源激酶（Chk）在C端酪氨酸残基上磷酸化Src家族激酶并负调节其激酶活性。尽管这一调节功能在生物学上非常重要，但Csk和Chk也是研究PTK催化和调节结构基础的优秀模型酶。在本文中，我们回顾了Csk和Chk的结构功能研究，阐明了蛋白酪氨酸激酶的调节和催化机制。版权所有©2023 Sun and Ayrapetov。

Protein tyrosine kinases (PTKs) are a large enzyme family that regulates many cellular processes. The key to their broad role in signaling is their tunable substrate specificity and regulatory mechanisms that allow each to respond to appropriate regulatory signals and phosphorylate the correct physiological protein substrates. Thus, in addition to the general PTK catalytic platform, each PTK acquires unique structural motifs that confer a unique combination of catalytic and regulatory properties. Understanding the structural basis for these properties is essential for understanding and manipulating the PTK-based signaling networks in normal and cancer cells. C-terminal Src kinase (Csk) and its homolog, Csk-homologous kinase (Chk), phosphorylate Src family kinases on a C-terminal Tyr residue and negatively regulate their kinase activity. While this regulatory function is biologically essential, Csk and Chk have also been excellent model PTKs for dissecting the structural basis of PTK catalysis and regulation. In this article, we review the structure-function studies of Csk and Chk that shed light on the regulatory and catalytic mechanisms of protein tyrosine kinases in general.Copyright © 2023 Sun and Ayrapetov.