Wang Yuanxian, Wang Liqing, Gao Huihui, Gao Yao, Yang Changming, Ji Hong, Dong Wuzi
College of Animal Science and Technology, Northwest A&F University, Yangling 712100, China.
Animal Husbandry and Veterinary Station of Chenggu County, Hanzhong 723200, China.
Oncotarget. 2017 Sep 15;8(49):86043-86055. doi: 10.18632/oncotarget.20910. eCollection 2017 Oct 17.
Ubiquitin carboxyl-terminal hydrolase L1 (UCHL1), which is extensively expressed in vertebrates, is a deubiquitinating enzymes that inhibits the degradation of proteins by reversing ubiquitination modification. Herein, a 1087-bp sequence encoding UCHL1 was identified from the Chinese giant salamander (CGS; ). The coding sequences (CDS) of encoded a putative poly peptide of 222 amino acids. The CGS UCHL1 isoforms were more related to their human and mouse counterparts. The phylogenic tree of vertebrate UCHL1 indicated that CGS UCHL1 has the closest relationship with human UCHL1 (up to 73.99 %). Before the gonads of male CGSs matured, the peak level of UCHL1 expression in testes appeared in 3-year-old CGSs according to RT-qPCR and western blot. In adult testes, the level of UCHL1 protein was lower in the breeding period than in the post-breeding period, whereas the level of UCHL1 protein in interstitial fluid of adult CGS testes was higher during the breeding period than during the post-breeding period. In testicular seminiferous lobules in the developmental stage of CGSs, immunohistochemistry displayed three kinds of localizing patterns of UCHL1, including nuclear localization at half year old, cytoplasmic localization from one year to three years old, and extracellular localization in adult. In testicular seminiferous lobules of adult CGS, the different developmental germ cells were separated by cysts containing UCHL1 protein, but UCHL1 did not localize on the mature sperm. The results showed that extracellular UCHL1 loaded on exosomes, as a component of the homogeneous germ cell cysts, could regulate the synchronous development of sperm in testes of adult CGS.
泛素羧基末端水解酶L1（UCHL1）在脊椎动物中广泛表达，是一种去泛素化酶，可通过逆转泛素化修饰来抑制蛋白质降解。在此，从中国大鲵（CGS）中鉴定出一段编码UCHL1的1087 bp序列。该序列的编码序列（CDS）编码一个推定的222个氨基酸的多肽。CGS UCHL1亚型与人类和小鼠的对应物关系更为密切。脊椎动物UCHL1的系统发育树表明，CGS UCHL1与人类UCHL1的关系最为密切（高达73.99%）。根据RT-qPCR和蛋白质印迹法，在雄性CGS的性腺成熟之前，睾丸中UCHL1表达的峰值出现在3岁的CGS中。在成年睾丸中，繁殖期UCHL1蛋白水平低于繁殖后期，而成年CGS睾丸间质液中UCHL1蛋白水平在繁殖期高于繁殖后期。在CGS发育阶段的睾丸生精小叶中，免疫组织化学显示UCHL1有三种定位模式，包括半岁时的核定位、1岁至3岁时的细胞质定位以及成年时的细胞外定位。在成年CGS的睾丸生精小叶中，不同发育阶段的生殖细胞被含有UCHL1蛋白的囊肿分隔开，但UCHL1并不定位于成熟精子上。结果表明，作为同质生殖细胞囊肿的一个组成部分，负载在外泌体上的细胞外UCHL1可以调节成年CGS睾丸中精子的同步发育。
