Role of band 3 tyrosine phosphorylation in the regulation of erythrocyte glycolysis.
Role of band 3 tyrosine phosphorylation in the regulation of erythrocyte glycolysis.
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DOI：
10.1016/s0021-9258(20)64292-2
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发表时间：
1991-03
期刊：
影响因子：
--
通讯作者：
M. Harrison;P. Rathinavelu;P. Arese;R. Geahlen;P. Low
中科院分区：
文献类型：
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作者：
M. Harrison;P. Rathinavelu;P. Arese;R. Geahlen;P. Low
先前的研究表明，人红细胞阴离子转运蛋白带 3 的体外酪氨酸磷酸化可阻止各种糖酵解酶与细胞质尾部 N 末端的结合。由于这些酶在其结合状态下受到抑制，因此红细胞中带 3 酪氨酸磷酸化的功能结果应该是激活这些酶并提高糖酵解。我们使用一种新颖的测定法来寻找带 3 酪氨酸磷酸化的各种增强剂，该测定旨在测量带 3 酪氨酸磷酸化/糖酵解酶结合位点的磷酸酪氨酸水平。该测定测量了重新密封的红细胞内合成的带 3 肽的磷酸化程度。使用该测定法，发现三种不同的化合物（均为温和氧化剂）可刺激带 3 的酪氨酸磷酸化。还发现所有三种化合物均可提高完整红细胞的糖酵解速率。此外，还发现抗肿瘤药物阿霉素可以协同阻止这些药物刺激带 3 酪氨酸磷酸化和红细胞糖酵解。这些结果表明，人红细胞中的蛋白酪氨酸激酶可能具有通过带 3 的酪氨酸磷酸化来调节糖酵解的功能。
Previous studies demonstrated that thein vitrotyrosine phosphorylation of the human erythrocyte anion transporter, band 3, prevented the binding of various glycolytic enzymes to the N terminus of the cytoplasmic tail. Since these enzymes are inhibited in their bound state, the functional consequences of band 3 tyrosine phosphorylation in the red cell should be to activate the enzymes and elevate glycolysis. We searched for various enhancers of band 3 tyrosine phosphorylation using a novel assay designed to measure the phosphotyrosine levels at the band 3 tyrosine phosphorylation/glycolytic enzyme-binding site. This assay measures the extent of phosphorylation of a synthetic band 3 peptide entrapped within resealed red cells. Using this assay, three distinct compounds, all mild oxidants, were found to stimulate the tyrosine phosphorylation of band 3. All three compounds were also found to elevate glycolytic rates in intact erythrocytes. Moreover, the antitumor drug adriamycin was found to coordinately prevent these agents from stimulating both band 3 tyrosine phosphorylation and erythrocyte glycolysis. These results suggest a possible function for a protein tyrosine kinase in human erythrocytes, to regulate glycolysis through the tyrosine phosphorylation of band 3.