Cloning and Characterization of Protein Tyrosine Kinases

蛋白酪氨酸激酶的克隆和表征

• 批准号: 6559068
• 负责人: Daniel W. McVicar
• 金额: --
• 依托单位: DIVISION OF BASIC SCIENCES - NCI
• 依托单位国家: 美国
• 资助国家: 美国
• 起止时间: 至
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/6559068
• 关键词: T cell receptor; T lymphocyte; enzyme activity; genetically modified animals; human tissue; laboratory mouse; leukocyte activation /transformation; molecular cloning; natural killer cells; protein structure function; protein tyrosine kinase

This project involves the continued characterization of protein tyrosine kinases (PTK) cloned from natural killer cells. The primary emphasis of this project is the study of a PTK that has significant homology to the carboxyl-terminal Src kinase (Csk); the Csk homolgous kinase, Chk (previously known as Lsk). Before the discovery of Chk, Csk was the only PTK known to phosphorylate the conserved carboxyl-terminal tyrosine of Src family kinases and down-regulate their catalytic activity. Unlike Csk, which is ubiquitously expressed, Chk is expressed primarily in hematopoietic cells. We have shown Chk expression to be inducible in both T cells and peripheral blood monocytes. However, our studies have shown that unlike Csk, Chk expression does not inhibit T cell receptor function. In an effort to understand the different roles of Csk and Chk in T cells, we have identified Chk Src homology (SH)2 domain binding proteins from T cell lysates. This year we published studies identifying paxillin as a Chk binding protein. In addition, screening of a phage display library with the Chk SH3 domain yielded a proline rich peptide that may represent a Chk SH3 ligand. Computer searches have identified possible protein candidates as Chk interaction protiens. These leads are now under investigation. Together with our continuing studies of the expression of Chk and investigation of Chk knockout mice, this work should shed light on the molecular control of macrophage and/or T cell and NK cell adherence and immune regulation.

该项目涉及从天然杀伤细胞克隆的蛋白酪氨酸激酶（PTK）的持续表征。该项目的主要重点是对与羧基末端SRC激酶（CSK）具有重要同源性PTK的研究。 CSK同位激酶CHK（以前称为LSK）。在发现CHK之前，CSK是唯一已知的PTK，可以磷酸化SRC家族激酶的保守羧基 - 末端酪氨酸并下调其催化活性。与普遍表达的CSK不同，CHK主要在造血细胞中表达。我们已经显示CHK表达在T细胞和外周血单核细胞中均可诱导。但是，我们的研究表明，与CSK不同，CHK表达不会抑制T细胞受体功能。为了了解CSK和CHK在T细胞中的不同作用，我们已经确定了来自T细胞裂解物的CHK SRC同源性（SH）2结构域结合蛋白。今年，我们发表的研究将帕西林鉴定为CHK结合蛋白。此外，用CHK SH3结构域对噬菌体显示库进行筛选产生了富含脯氨酸的肽，该肽可能代表CHK SH3配体。计算机搜索已将可能的蛋白质候选物确定为CHK相互作用蛋白质。这些线索现在正在调查中。加上我们对CHK表达的持续研究以及对CHK敲除小鼠的研究，这项工作应阐明巨噬细胞和/或T细胞以及NK细胞粘附和免疫调节的分子控制。