Ca2+-stores in sperm: their identities and functions.
Ca2+-stores in sperm: their identities and functions.
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DOI：
10.1530/rep-09-0134
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发表时间：
2009-09
期刊：
影响因子：
--
通讯作者：
Publicover S
中科院分区：
文献类型：
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作者：
Costello S;Michelangeli F;Nash K;Lefievre L;Morris J;Machado-Oliveira G;Barratt C;Kirkman-Brown J;Publicover S
细胞内钙库在细胞内[Ca 2 +]i的调节和复杂[Ca 2 +]信号如振荡和波的产生中起着核心作用。Ca 2+信号在精子细胞中具有特别重要的意义，在精子细胞中，Ca 2+信号是许多关键活动（包括获能、超活化、趋化性和顶体反应）的中心调节剂，但成熟精子缺乏内质网和其他几种细胞器，这些细胞器在体细胞中充当Ca 2+储存。在这里，我们审查（i）的分子组件（泵和通道），这是功能上显着的体细胞的钙库的活动在精子中的表达的证据和（ii）的证据存在的功能性钙库在精子中。这一证据支持哺乳动物精子中至少存在两个贮藏细胞器，一个位于顶体区域，另一个位于精子颈部和中段区域。然后，我们继续讨论这些细胞器的可能身份和它们的离散功能：顶体自身分泌的调节和精子颈部膜细胞器（可能还有线粒体）鞭毛活性和超活化的调节。最后，我们考虑的能力，精子离散控制动员这些商店和存储的Ca 2+在精子颈部/中段与CatSper通道的功能相互作用的主要部分在调节哺乳动物精子的活动。
Intracellular Ca2+ stores play a central role in the regulation of cellular [Ca2+]i and the generation of complex [Ca2+] signals such as oscillations and waves. Ca2+ signalling is of particular significance in sperm cells, where it is a central regulator in many key activities (including capacitation, hyperactivation, chemotaxis and acrosome reaction) yet mature sperm lack endoplasmic reticulum and several other organelles which serve as Ca2+ stores in somatic cells. Here we review (i) the evidence for the expression in sperm of the molecular components (pumps and channels) which are functionally significant in the activity of Ca2+ stores of somatic cells and (ii) the evidence for the existence of functional Ca2+ stores in sperm. This evidence supports the existence of at least two storage organelles in mammalian sperm, one in the acrosomal region and another in the region of the sperm neck and midpiece. We then go on to discuss the likely identity of these organelles and their discrete functions: regulation by the acrosome of its own secretion and regulation by membranous organelles at the sperm neck (and possibly by the mitochondria) of flagellar activity and hyperactivation. Finally we consider the ability of the sperm discretely to control mobilisation of these stores and the functional interaction of stored Ca2+ at the sperm neck/midpiece with CatSper channels in the principal piece in regulation of the activities of mammalian sperm.