Animal Resource Research Center, Konkuk University, Seoul, South Korea.
Theriogenology. 2010 Feb;73(3):273-81. doi: 10.1016/j.theriogenology.2009.09.010. Epub 2009 Nov 13.
A novel testis-derived membrane occupation and recognition nexus (MORN)-motif protein was identified in mouse testis (MOPT) by subtraction screening methods and found to be localized on chromosome 17E3, spanning approximately 7kb. Sequence analysis showed that MOPT contains 669 base pair nucleotides of open reading frame and the corresponding 79 amino acids. The protein is predicted to have theoretical molecular mass of 9000 Da and an expected isoelectric point of 5.8 and seems to have unique sequences except for MORN-motif domain. The transcript of MOPT is highly and specifically expressed in adult testis as well as skeletal muscle. Moreover, MOPT transcript and protein are confined mainly to round and elongated spermatids, except for a few individual dispersed spermatocytes, and increase in abundance at subsequent stages. MOPT first appeared in the proacrosomic vesicles of the early Golgi phase spermatids and was translocated from the head cap of elongated spermatid to the nucleus of mature spermatozoa at the final stage of spermiogenesis. Our study suggests that MOPT may play an important role in dynamic regulation of acrosome biogenesis during late spermiogenesis.
一种新的睾丸膜占领和识别连接蛋白（MORN）基序蛋白（MOPT），通过差减筛选方法在小鼠睾丸中被鉴定，定位于 17E3 染色体上，跨度约 7kb。序列分析表明，MOPT 含有 669 个碱基对的开放阅读框和相应的 79 个氨基酸。该蛋白预测具有 9000 Da 的理论分子量和 5.8 的预期等电点，除了 MORN 基序域外，似乎具有独特的序列。MOPT 的转录本在成年睾丸和骨骼肌中高度特异性表达。此外，MOPT 转录本和蛋白主要局限于圆形和拉长的精子细胞，除了少数分散的精母细胞外，在后续阶段丰度增加。MOPT 首先出现在早期高尔基期精子细胞的前顶体小泡中，并在精子发生的最后阶段从拉长精子头部帽部转移到成熟精子的核中。我们的研究表明，MOPT 可能在晚期精子发生过程中顶体生物发生的动态调节中发挥重要作用。
