High water permeability of human spermatozoa is mercury-resistant and not mediated by CHIP28.
High water permeability of human spermatozoa is mercury-resistant and not mediated by CHIP28.
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人类精子的高透水性具有耐汞性，并且不受 CHIP28 介导。
DOI：
10.1095/biolreprod52.4.913
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发表时间：
1995
影响因子：
3.6
通讯作者：
Critser,JK
中科院分区：
文献类型：
--
作者：
Liu,C;Gao,D;Preston,GM;McGann,LE;Benson,CT;Critser,ES;Critser,JK
一种表观分子量为 28 kDa 的新型整合膜蛋白 (CHIP28) 首次从人红细胞中分离出来，现在被认为是水通道蛋白。这种蛋白质的表达已在其他几种细胞类型中发现，这些细胞类型都需要高透水性才能发挥其功能。最近的研究表明，人类精子的水渗透性 (Lp) 是哺乳动物细胞中最高的。加上人类精子对Lp的低活化能，这表明CHIP28水通道可能存在于人类精子的质膜中。然而，我们目前的研究并不支持这一假设。通过使用抗人红细胞 CHIP28 蛋白的抗体对人精子质膜蛋白进行蛋白质印迹分析，结果表明人精子在其细胞表面不表达 CHIP28 蛋白 (n = 10)。与蛋白质印迹结果一致，氯化汞（HgCl2），一种已知的水通道阻断剂，未能降低人类精子的渗透水渗透性。计算得出的 Lp 值，对照组为 1.30 ± 0.29 µm/min/atm（n = 16；平均值 ± SEM），对照组为 1.31 ± 0.29（n = 9；平均值 ± SEM）、1.04 ± 0.27（n = 11；平均值 ± SEM）和 1.34 ± 0.19（n = 6；平均值 ± SEM）。 10μM、30μM 和 50μM HgCl2 处理组。这些 Lp 值没有不同 (p> 0.05)。相比之下，相同浓度的HgCl2显着阻断了渗透水穿过人红细胞膜的转运。这些数据强烈表明，人类精子质膜的高透水性并非由 CHIP 造成，而可能是由其他耐汞的水通道蛋白介导的。
A novel integral membrane protein with an apparent molecular mass of 28 kDa (CHIP28) was first isolated from human erythrocytes and is now recognized as a water channel protein. The expression of this protein has been found in several other cell types that all require high water permeability for their functions. Recent studies have shown that the water permeability (Lp) of human spermatozoa is among the highest reported for mammalian cells. Together with the low activation energy of human spermatozoa for Lp, this suggests that CHIP28 water channel may be present in the plasma membrane of human spermatozoa. However, our current studies do not support this hypothesis. Results from Western blot analysis on human sperm plasma membrane proteins, performed through use of an antibody against human erythrocyte CHIP28 protein, indicated that human spermatozoa do not express CHIP28 protein on their cell surface (n = 10). Consistent with the Western blot finding, mercuric chloride (HgCl2), a known water channel blocker, failed to reduce the osmotic water permeability of human spermatozoa. The calculated Lpvalues were 1.30 ± 0.29 µm/min/atm (n = 16; mean ± SEM) for the control group and 1.31 ± 0.29 (n = 9; mean ± SEM), 1.04 ± 0.27 (n = 11; mean ± SEM), and 1.34 ± 0.19 (n = 6; mean ± SEM), respectively, for the 10μM, 30μM, and 50μM HgCl2-treated groups. These Lpvalues are not different (p> 0.05). In contrast, the same concentration of HgCl2significantly blocked the osmotic water transport across the membrane of human erythrocytes. These data strongly suggest that the high water permeability of human sperm plasma membranes is not due to CHIP but may be mediated by other water channel proteins that are mercury-resistant.