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.

该项目涉及对从自然杀伤细胞克隆的蛋白酪氨酸激酶 (PTK) 进行持续表征。该项目的主要重点是研究与羧基末端 Src 激酶 (Csk) 具有显着同源性的 PTK； Csk 同源激酶 Chk（以前称为 Lsk）。在 Chk 发现之前，Csk 是唯一已知能够磷酸化 Src 家族激酶的保守羧基末端酪氨酸并下调其催化活性的 PTK。与普遍表达的 Csk 不同，Chk 主要在造血细胞中表达。我们已经证明 Chk 表达在 T 细胞和外周血单核细胞中都是可诱导的。然而，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，我们从 T 细胞裂解物中鉴定出 Chk Src 同源 (SH)2 结构域结合蛋白。今年，我们发表了将桩蛋白鉴定为 Chk 结合蛋白的研究。此外，用 Chk SH3 结构域筛选噬菌体展示文库产生了富含脯氨酸的肽，其可能代表 Chk SH3 配体。计算机搜索已确定可能的候选蛋白质为 Chk 相互作用蛋白。这些线索目前正在接受调查。结合我们对 Chk 表达的持续研究以及对 Chk 敲除小鼠的研究，这项工作应该有助于阐明巨噬细胞和/或 T 细胞和 NK 细胞粘附和免疫调节的分子控制。