Hess H, Heid H, Zimbelmann R, Franke W W
Division for Cell Biology, German Cancer Research Center, Heidelberg.
Exp Cell Res. 1995 May;218(1):174-82. doi: 10.1006/excr.1995.1145.
The cytoskeletal calyx of mammalian sperm heads surrounding the basolateral part of the nucleus contains two kinds of basic proteins: Calicin, a polypeptide of approximate M(r) 60,000 as estimated from SDS-PAGE, and the group of the very basic cylicins (pI > 10.0), formerly designated as "multiple-band polypeptides." Recently, bovine cylicin I has been cDNA cloned and identified as a new type of a cytoskeletal protein, which contains numerous Lys-Lys-Asp tripeptides accumulated in nine central repetitive units predicted to form alpha-helices. We now report the cDNA cloning and localization of a second species of cylicin, bovine cylicin II, present in bovine and human sperm heads: Cylicin II (488 amino acids, M(r) 53,561, pI 10.55) shows the same prominent molecular characteristics as cylicin I, including a high content of charged amino acids, the abundance of Lys-Lys-Asp tripeptides, and repetitive units of presumably alpha-helical configuration, but also presents some differences. As with cylicin I mRNA, the 2.6-kb mRNA has also been shown to be specifically expressed in testis. The possible existence of a larger cylicin multigene family and its contribution to the cytoskeleton and the morphogenesis of the sperm head are discussed.
钙结合蛋白，一种从SDS-PAGE估计其分子量约为60,000的多肽，以及一组碱性很强的环蛋白（pI>10.0），以前被称为“多带多肽”。最近，牛环蛋白I已被克隆cDNA并鉴定为一种新型的细胞骨架蛋白，它含有大量在九个预测形成α螺旋的中央重复单元中积累的Lys-Lys-Asp三肽。我们现在报告第二种环蛋白——牛环蛋白II的cDNA克隆和定位，它存在于牛和人类的精子头部：环蛋白II（488个氨基酸，分子量53,561，pI 10.55）与环蛋白I具有相同的突出分子特征，包括高含量的带电荷氨基酸、丰富的Lys-Lys-Asp三肽以及可能为α螺旋构型的重复单元，但也存在一些差异。与环蛋白I mRNA一样，2.6-kb的mRNA也已被证明在睾丸中特异性表达。本文讨论了更大的环蛋白多基因家族可能的存在及其对精子头部细胞骨架和形态发生的作用。
