Reinhart W H, Sung L A, Schuessler G B, Chien S
Biochim Biophys Acta. 1986 Nov 6;862(1):1-7. doi: 10.1016/0005-2736(86)90462-1.
The normal, discoid shape of red blood cells represents an equilibrium between two opposing factors, i.e., stomatocytic and echinocytic transformations. Most stomatocytic agents were found to be inhibitors of calmodulin, a regulator of the phosphorylation of membrane proteins. We determined whether red cell shape transformations could be caused by changes in phosphorylation of membrane proteins, specifically the cAMP-dependent phosphorylation of ankyrin and band 4.1. Red blood cells were incubated with 32P and 100 microM chlorpromazine (stomatocytic transformation) or 30 mM sodium salicylate (echinocytic transformation) for various time intervals. Ghost membrane proteins were examined by polyacrylamide gel electrophoresis and autoradiography. Spectrin (beta-chain), ankyrin, band 3, band 4.1 and 4.9 were phosphorylated. No change was found in the degree and pattern of phosphorylation after stomatocytic transformation. Salicylate caused a reversible inhibition of transmembranous phosphate transport in both directions. The results indicate that the stomatocytic transformation induced by chlorpromazine and the echinocytic transformation induced by salicylate do not involve a change in phosphorylation, but that the echinocytic transformation induced by salicylate is associated with an inhibition of transmembranous transport of phosphate. Studies with salicylate suggest that the phosphorylation sites of band 3 are found mainly on the endofacial side of the membrane.
红细胞正常的盘状形态代表了两种相反因素之间的平衡，即口形红细胞和棘形红细胞转化。大多数口形红细胞诱导剂被发现是钙调蛋白的抑制剂，钙调蛋白是膜蛋白磷酸化的调节剂。我们确定红细胞形态转化是否可能由膜蛋白磷酸化的变化引起，特别是锚蛋白和带4.1的环磷酸腺苷（cAMP）依赖性磷酸化。将红细胞与32P和100微摩尔氯丙嗪（口形红细胞转化）或30毫摩尔水杨酸钠（棘形红细胞转化）孵育不同时间间隔。通过聚丙烯酰胺凝胶电泳和放射自显影检查空泡膜蛋白。血影蛋白（β链）、锚蛋白、带3、带4.1和4.9被磷酸化。口形红细胞转化后磷酸化程度和模式未发现变化。水杨酸盐在两个方向上均引起跨膜磷酸盐转运的可逆抑制。结果表明，氯丙嗪诱导的口形红细胞转化和水杨酸盐诱导的棘形红细胞转化不涉及磷酸化变化，但水杨酸盐诱导的棘形红细胞转化与磷酸盐跨膜转运的抑制有关。用水杨酸盐进行的研究表明，带3的磷酸化位点主要位于膜的内表面。
