Human testicular protein TPX1/CRISP-2:: localization in spermatozoa, fate after capacitation and relevance for gamete interaction
Human testicular protein TPX1/CRISP-2:: localization in spermatozoa, fate after capacitation and relevance for gamete interaction
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DOI：
10.1093/molehr/gah156
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发表时间：
2005-04-01
影响因子：
4
通讯作者：
Cuasnicú, PS
中科院分区：
文献类型：
--
作者：
Busso, D;Cohen, DJ;Cuasnicú, PS
睾丸蛋白Tpx-1，也称为CRISP-2，是一种富含半胱氨酸的分泌蛋白，特异性表达于男性生殖道。由于人类蛋白质的信息仅限于其基因的鉴定和表达，在这项工作中，我们研究了人类Tpx-1（TPX 1）在精子中的存在和定位，获能和顶体反应（AR）后的命运，以及其可能参与配子相互作用。间接免疫荧光研究显示，在活的或固定的非透化精子中没有显着的染色，相反，在透化精子的顶体区域有明确的标记。这些结果以及蛋白质提取程序的补充证据强烈支持TPX 1主要是新鲜精子中的顶体内蛋白。在体外获能和离子载体诱导的AR后，TPX 1仍然与顶体的赤道段相关。获能和AR前后TPX 1的电泳迁移率没有差异，表明该蛋白在这些过程中不会发生蛋白水解修饰。通过仓鼠卵母细胞穿透试验评价TPX 1可能参与配子相互作用。在配子共孵育过程中，抗TPX 1的存在对穿透的无透明带仓鼠卵母细胞的百分比产生了显著的剂量依赖性抑制，而不影响精子活力、AR或精子与卵母细胞的结合。总之，这些结果表明，人TPX 1将是精子顶体的组分，其在获能和AR后仍与精子相关，并且与精子-卵母细胞相互作用相关。
Testicular protein Tpx-1, also known as CRISP-2, is a cysteine-rich secretory protein specifically expressed in the male reproductive tract. Since the information available on the human protein is limited to the identification and expression of its gene, in this work we have studied the presence and localization of human Tpx-1 (TPX1) in sperm, its fate after capacitation and acrosome reaction (AR), and its possible involvement in gamete interaction. Indirect immunofluorescence studies revealed the absence of significant staining in live or fixed non-permeabilized sperm, in contrast to a clear labelling in the acrosomal region of permeabilized sperm. These results, together with complementary evidence from protein extraction procedures strongly support that TPX1 would be mainly an intra-acrosomal protein in fresh sperm. After in vitro capacitation and ionophore-induced AR, TPX1 remained associated with the equatorial segment of the acrosome. The lack of differences in the electrophoretic mobility of TPX1 before and after capacitation and AR indicates that the protein would not undergo proteolytical modifications during these processes. The possible involvement of TPX1 in gamete interaction was evaluated by the hamster oocyte penetration test. The presence of anti-TPX1 during gamete co-incubation produced a significant and dose-dependent inhibition in the percentage of penetrated zona-free hamster oocytes without affecting sperm motility, the AR or sperm binding to the oolema. Together, these results indicate that human TPX1 would be a component of the sperm acrosome that remains associated with sperm after capacitation and AR, and is relevant for sperm - oocyte interaction.