一个新的人类精子发生相关蛋白激酶cDNA的克隆

Cloning and Characterization of a New Human Spermatogenesis-related Protein Kinase cDNA

蛋白磷酸化被认为在精子发生过程中起重要作用 .从人类胎脑cDNA文库中得到 2个克隆 ,分别长1840bp和 15 71bp ,后者仅比前者在 3′非翻译区少了约 30 0个核苷酸 ,二者拟编码 32 2个氨基酸残基 ,基序分析发现其中含有 1段明显的蛋白激酶基序 .Northern杂交显示其在睾丸中有显著表达 ,暂命名为精子发生相关蛋白激酶 .原位杂交表明精子发生相关蛋白激酶基因在性成熟小鼠睾丸中主要表达在生精小管的外层细胞中 ,而这一层细胞主要包含分裂活跃的精原细胞和初级精母细胞 .提示精子发生相关蛋白激酶可能在精子发生过程中起着比较重要的作用 .

Protein phosphorylation is considered to be one of the important regulatory events in spermatogenesis. Present paper reported that two cDNA clones were isolated from a human fetal brain cDNA library. One cDNA is 1 840 bp and another one is 1 571 bp which is just about 300 bp shorter than the 1 840 bp clone at 3′ untranslated region. Both cDNAs encode a putative protein composed of 322 amino acids. Motif analysis revealed there is a protein kinase motif in the amino acid sequence. Northern blot analysis indicated that both cDNAs were predominantly expressed in testis, so it's denoted SPK (Spermatogenesis related Protein Kinase). Results of in situ hybridization revealed the SPK mRNA was distributed in the outer cell layer of seminiferous tubules, which is mainly composed of spermatogonia and primary spermatocytes. These observations suggest that the SPK may be involved in the process of spermatogeneis.