Primary structure of mouse proacrosin deduced from the cDNA sequence and its gene expression during spermatogenesis.
Primary structure of mouse proacrosin deduced from the cDNA sequence and its gene expression during spermatogenesis.
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从 cDNA 序列推导出小鼠顶体素原的一级结构及其在精子发生过程中的基因表达。
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发表时间：
1990
期刊：
影响因子：
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通讯作者：
Yuji Arai
中科院分区：
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作者：
S. Kashiwabara;Tadashi Baba;Masayasu Takada;Ken Watanabe;Yuriko Yano;Yuji Arai
在本研究中，我们确定了小鼠顶体酶的cDNA克隆从睾丸λ gt 11库。推导的氨基酸序列表明，小鼠顶体酶最初合成为单链多肽，具有16个残基的信号肽，随后是23个残基的轻链，然后是394个残基的重链;小鼠顶体酶酶原含有417个氨基酸残基，计算分子量为46，小鼠顶体蛋白原的cDNA衍生序列显示出与人和猪顶体蛋白原以及牛胰蛋白酶的主要部分的高度相似性，包括活性位点残基，底物的识别位点，12个半胱氨酸残基的位置，和两个潜在的N-糖基化位点。序列同源性表明，小鼠顶体酶原转化为成熟的顶体酶，其由轻链和重链组成，结合分子量为35，587 Da，通过切割Arg 23和IIe 24之间的肽键，并依次去除23-，26-和50-残基COOH-末端片段。用北方杂交分析小鼠不同组织的RNA，顶体酶基因转录本只存在于睾丸。1,800碱基顶体酶信息在18日龄睾丸中首次被检测到。在睾丸发育的同时，一些顶体酶mRNA实际上与多聚核糖体相关。同时，原位杂交分析表明顶体酶基因只在圆形精子细胞中表达。因此，最有可能的是，小鼠顶体酶基因的转录及其mRNA的随后翻译首先发生在圆形精子细胞的早期阶段，并且顶体酶信息不受翻译控制。
In the present study, we identified cDNA clones of mouse acrosin from a testis lambda gt11 library. The deduced amino acid sequence indicates that mouse acrosin is initially synthesized as a single-chain polypeptide with a 16-residue signal peptide followed by a 23-residue light chain and then a 394-residue heavy chain; mouse acrosin zymogen contains 417 amino acid residues with a calculated molecular mass of 46,993 Da. The cDNA-derived sequence of mouse proacrosin shows a high degree of similarity with human and porcine proacrosins and major portions of bovine trypsin, including the active site residues, the recognition site for substrate, the location of 12 cysteine residues, and two potential N-glycosylation sites. The sequence homology suggests that mouse proacrosin is converted to a mature acrosin, which consists of the light and heavy chains with a combined molecular mass of 35,587 Da, by cleavage of the peptide bond between Arg23 and IIe24, and sequential removal of 23-, 26-, and 50-residue COOH-terminal segments. Using Northern blot analysis of RNAs from various mouse tissues, the acrosin gene transcript was present only in testis. The 1,800-base acrosin message was first detectable in 18-day-old testis. At the same time of testicular development, some of the acrosin mRNA was actually associated with polysomes. Also, in situ hybridization analysis suggests that the acrosin gene is expressed only in the round spermatid. Therefore, it is most likely that transcription of the mouse acrosin gene and subsequent translation of its mRNA first occur in the early stages of the round spermatid, and that the acrosin message is not under translational control.