Regulation of protein tyrosine phosphorylation in human sperm by a calcium/calmodulin-dependent mechanism: Identification of a kinase anchor proteins as major substrates for tyrosine phosphorylation
Regulation of protein tyrosine phosphorylation in human sperm by a calcium/calmodulin-dependent mechanism: Identification of a kinase anchor proteins as major substrates for tyrosine phosphorylation
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DOI：
10.1006/dbio.1996.0301
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发表时间：
1996-11-25
影响因子：
2.7
通讯作者：
Moss, SB
中科院分区：
文献类型：
--
作者：
Carrera, A;Moos, J;Moss, SB
信号转导途径调节哺乳动物精子功能的各个方面。当人类精子在支持获能的培养基中孵育时，蛋白质以时间依赖性的方式变得酪氨酸磷酸化。这种磷酸化被蛋白酪氨酸激酶抑制剂染料木黄酮抑制。磷酸化也减少精子孵育时，无论是在细胞外Ca 2+浓度增加的存在下，或在培养基中含有Ca 2+离子载体A23187。这种Ca 2+诱导的去磷酸化是钙调蛋白依赖性的，表明钙调神经磷酸酶参与其中。在这方面，钙调磷酸酶抑制剂溴氰菊酯抑制钙离子载体诱导的去磷酸化。有限数量的M（r）80，000 - 105，000多肽是人类精子中最主要的含磷酸酪氨酸蛋白。与小鼠精子中含有酪氨酸磷酸化的己糖激酶亚型不同，人类精子中未检测到含有磷酸酪氨酸的己糖激酶。大多数酪氨酸磷酸化的蛋白质是Triton X-100不溶性的，并且定位于鞭毛的主要部分，在该区域发现了细胞骨架纤维鞘。M（r）82，000和97，000的突出的含磷酸酪氨酸的蛋白质被鉴定为小鼠精子AKAP 82的人类同源物，AKAP 82是主要的纤维鞘蛋白，其前体多肽pro-AKAP 82，分别这些蛋白质是A激酶锚蛋白，将蛋白激酶A螯合到亚细胞位置的多肽。总之，这些结果表明，蛋白质酪氨酸磷酸化可能是一个信号转导级联调节有关的获能和/或在哺乳动物精子的运动性事件的一部分，酪氨酸激酶和cAMP信号通路之间的相互关系存在于这些细胞。(C)出版社：Academic Press，Inc.
Signal transduction pathways regulate various aspects of mammalian sperm function. When human sperm were incubated in a medium supporting capacitation, proteins became tyrosine-phosphorylated in a time-dependent manner. This phosphorylation was inhibited by genistein, a protein tyrosine kinase inhibitor. Phosphorylation was also reduced when sperm were incubated either in the presence of increasing concentrations of extracellular Ca2+ or in a medium containing the Ca2+ ionophore A23187. This Ca2+-induced dephosphorylation was calmodulin-dependent, suggesting that calcineurin was involved. Zn this regard, the calcineurin inhibitor deltamethrin inhibited the Ca2+ ionophore-induced dephosphorylation. A limited number of M(r) 80,000-105,000 polypeptides were the most prominent phosphotyrosine-containing proteins present in human sperm. Unlike mouse sperm, which contains a tyrosine-phosphorylated isoform of hexokinase, a phosphotyrosine-containing hexokinase in human sperm was not detected. Most of the tyrosine-phosphorylated proteins were Triton X-100-insoluble and were localized to the principal piece of the flagellum, the region where the cytoskeletal fibrous sheath is found. Prominent phosphotyrosine-containing proteins of M(r) 82,000 and 97,000 were identified as the human homologues of mouse sperm AKAP82, the major fibrous sheath protein, and pro-AKAP82, its precursor polypeptide, respectively. These proteins are A Kinase Anchor Proteins, polypeptides that sequester protein kinase A to subcellular locations. Taken together, these results suggest that protein tyrosine phosphorylation may be part of a signal transduction cascade(s) regulating events pertaining to capacitation and/or motility in mammalian sperm and that an interrelationship between tyrosine kinase and cAMP signaling pathways exists in these cells. (C) 1996 Academic Press, Inc.