Analysis of New NAD-cleavage Enzymes Involved in Signal Transduction System

信号转导系统中涉及的新型 NAD 裂解酶的分析

基本信息

批准号：
08458193
负责人：
KATADA Toshiaki
金额：
$ 4.35万
依托单位：
The University of Tokyo (Faculty of Pharmaceutical Sciences)
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (B)
财政年份：
1996
资助国家：
日本
起止时间：
1996 至无数据
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-08458193/
关键词：
NAD Cyclic ADP-ribose NADase G proteins CD38 Tyrosine phosphorylation Signal transduction 環状ADPリボース

项目摘要

The human cell surface antigen CD38, which has an amino acid sequence homologous to Aplysia ADP-ribosyl cyclase, is a 46-kDa type II glycoprotein with a single-transmembrane domain. We previously demonstrated that the extracellular domain of CD38 exhibits NAD^+ glycohydrolase (NADase) activity and that the ecto-form NADase activity induced by all-trans retinoic acid (RA) in HL-60 cells is due to CD38. CD38 catalyzes not only the hydrolysis of NAD^+ but also the formation and hydrolysis of cyclic ADP-ribose, which is a novel candidate that mediates Ca^<2+> release from intracellular Ca^<2+> stores. In the present study, we obtained the following findings. 1. Stimulation of RA-differentiated HL-60 cells with anti-CD38 monoclonal antibodies (mAbs) induced rapid tyrosine phosphorylation of cellular proteins with the molecular weights of 120,000,87,000 and 77,000. One of the prominent phosphorylated proteins was identified as the c-cbl proto-oncogene product, p120^<c-cbl>.2. Superoxide formation in response to formyl-Met-Leu-Phe was markedly enhanced by the anti-CD38 mAbs in the differentiated HL-60 cells. 3. The epitopes recognized by these agonistic mAbs stimulating protein tyrosine phosphorylation were all mapped on the same carboxyl-terminal sequence of CD38, and the same sequence was also required for its ecto-NADase activity. 4. Fcgamma-II receptors appeared to be involved in the signal transduction pathway mediated through the agonistic anti-CD38 mAb-induced tyrosine phosphorylation of cellular proteins. 5. The expression of CD38 mRNA was mediated through nuclear RA receptors ; a RA receptor-responsive element was present in the first intron of CD38 gene.

人类细胞表面抗原CD38具有与Aplysia adp-ribosyl Cyclase同源的氨基酸序列，是具有单跨膜结构域的46 kDa II型糖蛋白。我们先前证明，CD38的细胞外结构域具有NAD^+糖脂酶（NADase）活性，并且在HL-60细胞中由全反式视黄酸（RA）诱导的ECTO形式的NADase活性是由于CD38引起的。 CD38不仅催化了NAD^+的水解，还催化了环状ADP-核糖的形成和水解，这是一种新型候选者，可介导Ca^<2+>从细胞内Ca^<2+>商店中释放。在本研究中，我们获得了以下发现。 1。用抗CD38单克隆抗体（MAB）刺激RA分化的HL-60细胞，诱导细胞蛋白的快速酪氨酸磷酸化，分子量为120,000,87,000和77,000。明显的磷酸化蛋白之一被鉴定为C-CBL原型癌基产品P120^<c-cbl> .2。分化的HL-60细胞中的抗CD38 mAb显着增强了对甲基 - 米尔 - phe的响应的超氧化物形成。 3。这些激动剂mAb识别的表位刺激蛋白酪氨酸磷酸化均在CD38的同一羧基末端序列上映射，并且其ECTO-NADase活性也需要相同的序列。 4。FCGAMMA-II受体似乎参与了通过激动剂抗CD38 mAb诱导的细胞蛋白的酪氨酸磷酸化介导的信号转导途径。 5。通过核RA受体介导CD38 mRNA的表达； CD38基因的第一个内含子中存在RA受体反应元件。