Tissue distribution and immunoreactivity of heme-regulated eIF-2 alpha kinase determined by monoclonal antibodies.
Tissue distribution and immunoreactivity of heme-regulated eIF-2 alpha kinase determined by monoclonal antibodies.
复制标题
通过单克隆抗体测定血红素调节的 eIF-2 α 激酶的组织分布和免疫反应性。
DOI：
10.1021/bi00223a037
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发表时间：
1991
期刊：
影响因子：
2.9
通讯作者：
London,IM
中科院分区：
文献类型：
--
作者：
Pal,JK;Chen,JJ;London,IM
Revised Manuscript Received December 3, 1990 abstract; A highly purified preparation of heme-regulated inhibitor (HRI), an eIF-2a kinase, from rabbit reticulocyte lysates has been used for generating monoclonal antibodies (mAB). Two hybridoma clones secreting HRI-specific antibodies (mAB A and mAB F) were obtained. Both antibodies immunoprecipitated biosynthetically labeled as well as phosphorylated HRI in reticulocyte lysates and also recognized denaturedHR! in a Western blot. In in vitro protein kinase assays, preincubation ofHRI with the antibodies significantly diminished bothautokinase and eIF-2a kinase activities. HRI from reticulocyte lysates could be quantitatively removed by immunoprecipitation with mAB F, and such HRI-depleted lysates were able to maintain protein synthesis under conditions of heme deficiency. With these monoclonal antibodies, HRI was detected only in the reticulocytes and bone marrow of anemic rabbits, among several rabbit tissues tested. The antibodies did not detect cross-reacting HRI in rat or human reticulocytes or in mouse erythroleukemic cells or human K562 cells even after induction of differentiation, although eIF-2a kinase activity was detected in them. Polyclonal anti-rabbit HRI antibody detected HRI in rat reticulocytes. However, no cross-reacting HRI was detected by polyclonal antibody in human reticulocytes or other cell types tested. These findings suggest that HRI is not ubiquitous, and may be erythroid-specific, and that it is antigenically different in
