Targeted deletion of Tssk1 and 2 causes male infertility due to haploinsufficiency
Targeted deletion of Tssk1 and 2 causes male infertility due to haploinsufficiency
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DOI：
10.1016/j.ydbio.2008.03.047
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发表时间：
2008-07-15
影响因子：
2.7
通讯作者：
Herr, John C.
中科院分区：
文献类型：
--
作者：
Xu, Bingfang;Hao, Zhonglin;Herr, John C.
定向删除 Tssk1 和 2 会产生雄性嵌合体，产生带有突变等位基因的精子/生精细胞，但该等位基因从未遗传给后代，表明由于单倍体不足而导致不育。嵌合体的形态缺陷包括无法形成细长的精子细胞、精母细胞和精子细胞凋亡以及附睾腔中出现大量圆形细胞。在人和小鼠中进一步研究了 TSSK2 的特征及其与底物 TSKS 的相互作用。睾丸中确认了激酶和底物的存在，同时首次揭示了精子中这两种蛋白质的持久性。通过对来自人类精子和小鼠睾丸提取物的 TSSK2/TSKS 复合物进行免疫共沉淀，建立了 TSSK2 和 TSKS 之间的体内结合相互作用。通过缺失作图确定了人 TSKS N 末端在酶结合中的作用。从小鼠睾丸和人类精子提取物中免疫沉淀的 TSKS 被主动磷酸化。 Ser281 被鉴定为小鼠 TSKS 中的磷酸化位点。这些结果证实了 TSSK 2 和 TSKS 持续存在于精子中，定义了 TSKS 的 N 末端在酶相互作用中的关键作用，将 Ser 281 鉴定为 TSKS 磷酸化位点，并表明 TSSK 1 和 2 在精子发生中不可或缺的作用。由爱思唯尔公司出版
Targeted deletion of Tssk1 and 2 resulted in male chimeras which produced sperm/spermatogenic cells bearing the mutant allele, however this allele was never transmitted to offspring, indicating infertility due to haploinsufficiency. Morphological defects in chimeras included failure to form elongated spermatids, apoptosis of spermatocytes and spermatids, and the appearance of numerous round cells in the epididymal lumen. Characterization of TSSK2 and its interactions with the substrate, TSKS, were further investigated in human and mouse. The presence of both kinase and substrate in the testis was confirmed, while persistence of both proteins in spermatozoa was revealed for the first time. In vivo binding interactions between TSSK2 and TSKS were established through co-immunoprecipitation of TSSK2/TSKS complexes from both human sperm and mouse testis extracts. A role for the human TSKS N-terminus in enzyme binding was defined by deletion mapping. TSKS immunoprecipitated from both mouse testis and human sperm extracts was actively phosphorylated. Ser281 was identified as a phosphorylation site in mouse TSKS. These results confirm both TSSK 2 and TSKS persist in sperm, define the critical role of TSKS' N-terminus in enzyme interaction, identify Ser 281 as a TSKS phosphorylation site and indicate an indispensable role for TSSK 1 and 2 in spermiogenesis. Published by Elsevier Inc.