H Hess, H Heid, R Zimbelmann, W W Franke
Division for Cell Biology, German Cancer Research Center, Heidelberg.
Experimental cell research 1995 MayThe 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.
H Hess, H Heid, R Zimbelmann, W W Franke. The protein complexity of the cytoskeleton of bovine and human sperm heads: the identification and characterization of cylicin II. Experimental cell research. 1995 May;218(1):174-82
PMID: 7737358
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