Abstract:
Tubulin polymerization-promoting protein2 (TPPP2) is one of the three paralogs of mammalian TPPP proteins. Its possible role in spermatogenesis is described in this narrative review. TPPP2 is expressed specifically in the male reproductive system, mainly in testes and sperm, and also in the epididymis. In testes, TPPP2 is exclusively expressed in elongating spermatids; in the epididymis, it is located in the middle piece of the sperm tail. TPPP2 is involved in spermiogenesis, in steps which are determinative for the formation and morphology of spermatids. The inhibition of TPPP2 decreases sperm motility (the curvilinear velocity of sperms), probably due to influencing mitochondrial energy production since TPPP2 knockout mice possess an impaired mitochondrial structure. There are data on the role of TPPP2 in various mammalian species: human, mouse, swine, and various ruminants; there is a significant homology among TPPP2s from different species. Experiments with Tppp2-/--mice show that the absence of TPPP2 results in decreased sperm count and serious dysfunction of sperm, including decreased motility; however, the in vitro capacitation and acrosome reaction are not influenced. The symptoms show that Tppp2-/--mice may be considered as a model for oligoasthenozoospermia.
摘要:
微管蛋白聚合促进蛋白2(TPPP2)是哺乳动物TPPP蛋白的三个旁系同源物之一。在这篇叙述性综述中描述了其在精子发生中的可能作用。TPPP2在男性生殖系统中特异性表达,主要在睾丸和精子中,还有附睾.在睾丸中,TPPP2仅在延伸的精子细胞中表达;在附睾中,它位于精子尾巴的中间部分。TPPP2参与精子发生,在确定精子形成和形态的步骤中。TPPP2的抑制降低精子运动性(精子的曲线速度),可能是由于影响线粒体能量产生,因为TPPP2敲除小鼠具有受损的线粒体结构。有关于TPPP2在各种哺乳动物物种中的作用的数据:人类,鼠标,猪,和各种反刍动物;来自不同物种的TPPP2s之间存在显着同源性。用Tppp2-/-小鼠进行的实验表明,缺乏TPPP2会导致精子数量减少和精子严重功能障碍,包括运动能力下降;然而,体外获能和顶体反应不受影响。症状表明Tppp2-/-小鼠可被视为少弱精子症的模型。