NUCLEOTIDE AND PREDICTED AMINO-ACID-SEQUENCES OF CLONED HUMAN AND MOUSE PREPROCATHEPSIN-B CDNAS
NUCLEOTIDE AND PREDICTED AMINO-ACID-SEQUENCES OF CLONED HUMAN AND MOUSE PREPROCATHEPSIN-B CDNAS
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DOI：
10.1073/pnas.83.20.7721
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发表时间：
1986-10-01
影响因子：
11.1
通讯作者：
STEINER, DF
中科院分区：
文献类型：
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作者：
CHAN, SJ;SANSEGUNDO, B;STEINER, DF
组织蛋白酶B是一种溶酶体巯基蛋白酶，可能具有额外的溶酶体外功能。为了进一步研究这种酶的结构、生物合成模式和细胞内分选，我们使用从人肝癌和肾噬菌体文库中分离的cDNA克隆确定了人和小鼠前组织蛋白原B的完整编码序列。核苷酸序列预测前组织蛋白酶原B的一级结构包含339个氨基酸，其组织如下：17个残基的NH 2-末端前肽序列，随后是62个残基的前肽区域，成熟（单链）组织蛋白酶B中的254个残基，以及COOH末端的6个残基延伸。来自三个物种（人、小鼠和大鼠）的组织蛋白酶原B序列的比较揭示了前肽之间的同源性相对保守，具有最小68%的序列同一性。特别地，前肽中可能具有功能重要性的两个保守序列包括潜在的糖基化位点和在位置59处存在单个半胱氨酸。三个序列的比较分析还表明，前组织蛋白酶B的加工是一个多步骤的过程，在此过程中可能产生酶活性中间体形式。cDNA克隆的可用性将有助于鉴定可能的活性或非活性中间进行形式以及研究组织蛋白酶B基因的转录调控。
Cathepsin B is a lysosomal thiol proteinase that may have additional extralysosomal functions. To further our investigations on the structure, mode of biosynthesis, and intracellular sorting of this enzyme, we have determined the complete coding sequences for human and mouse preprocathepsin B using cDNA clones isolated from human hepatoma and kidney phage libraries. The nucleotide sequences predict that the primary structure of preprocathepsin B contains 339 amino acids organized as follows: a 17-residue NH2-terminal prepeptide sequence followed by a 62-residue propeptide region, 254 residues in mature (single chain) cathepsin B, and a 6-residue extension at the COOH terminus. A comparison of procathepsin B sequences from three species (human, mouse, and rat) reveals that the homology between the propeptides is relatively conserved with a minimum of 68% sequence identity. In particular, two conserved sequences in the propeptide that may be functionally significant include a potential glycosylation site and the presence of a single cysteine at position 59. Comparative analysis of the three sequences also suggests that processing of procathepsin B is a multistep process, during which enzymatically active intermediate forms may be generated. The availability of the cDNA clones will facilitate the identification of possible active or inactive intermediate processive forms as well as studies on the transcriptional regulation of the cathepsin B gene.