REGULATION OF THE ASCARIS MAJOR SPERM PROTEIN (MSP) CYTOSKELETON BY INTRACELLULAR PH
REGULATION OF THE ASCARIS MAJOR SPERM PROTEIN (MSP) CYTOSKELETON BY INTRACELLULAR PH
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DOI：
10.1002/cm.970270302
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发表时间：
1994-01-01
影响因子：
--
通讯作者：
MOERLAND, TS
中科院分区：
文献类型：
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作者：
KING, KL;ESSIG, J;MOERLAND, TS
蛔虫（Ascaris suum）变形虫精子的发育和运动依赖于对其独特的主要精子蛋白（MSP）丝系统组装的精确控制。我们使用装载BCECF的细胞的荧光比成像来显示细胞内pH（pH(i)）参与体内控制MSP聚合。精子发生的标志是MSP组装-拆卸-重组的周期，与pH值的变化相一致(i)。在含有MSP的准晶纤维体精母细胞中，pH(i)为6.8，比精子细胞中的pH(i)高0.6个单位，精子细胞分解纤维体，不包含MSP细丝的集合。激活精子完成发育导致pH(i)迅速增加到6.4，并重新出现细丝。用弱酸处理精母细胞导致纤维体解体，而在弱碱基中孵育精母细胞则诱导MSP组装。精子中的MSP丝被组织成纤维复合物，从假足的前缘不断向后流动。这些细胞建立了假足的pH梯度，在纤维复合体聚集的前缘，pH(i)比在假足基部发生解体的地方高0.15个单位。这些细胞的酸化导致MSP细胞骨架解体并消除了pH梯度。酸的去除导致细胞骨架的重组，pH梯度的重建和运动的重新启动。在正常发育和运动的精子和响应pH(i)的化学操作的细胞中，MSP的组装优先发生在膜上。因此，我们认为精子中的丝组装是由ph敏感的msp -膜相互作用控制的。(C) 1994 Wiley-Liss, Inc。
The development and locomotion of the amoeboid sperm of the nematode, Ascaris suum, depend on precise control of the assembly of their unique major sperm protein (MSP) filament system. We used fluorescence ratio imaging of cells loaded with BCECF to show that intracellular pH (pH(i)) is involved in controlling MSP polymerization in vivo. Spermatogenesis is marked by a cycle of MSP assembly-disassembly-reassembly that coincides with changes in pH(i). In spermatocytes, which contain MSP in paracrystalline fibrous bodies, pH(i) was 6.8, 0.6 units higher than in spermatids, which disassemble the fibrous bodies and contain no assemblies of MSP filaments. Activation of spermatids to complete development resulted in rapid increase in pH(i) to 6.4 and reappearance of filaments. Treatment of spermatocytes with weak acids caused the fibrous bodies to disassemble whereas incubation of spermatids in weak bases induced MSP assembly. The MSP filaments in spermatozoa are organized into fiber complexes that flow continuously rearward from the leading edge of the pseudopod. These cells established a pseudopodial pH gradient with pH(i) 0.15 units higher at the leading edge, where fiber complexes assemble, than at the base of the pseudopod, where disassembly occurs. Acidification of these cells caused the MSP cytoskeleton to disassemble and abolished the pH gradient. Acid removal resulted in reassembly of the cytoskeleton, re-establishment of the pH gradient, and re-initiation of motility. MSP assembly in sperm undergoing normal development and motility and in cells responding to chemical manipulation of pH(i) occurs preferentially at membranes. Thus, we propose that filament assembly in sperm is controlled by pH-sensitive MSP-membrane interaction. (C) 1994 Wiley-Liss, Inc.