Isolation of bovine kidney leucine aminopeptidase cDNA: comparison with the lens enzyme and tissue-specific expression of two mRNAs.
Isolation of bovine kidney leucine aminopeptidase cDNA: comparison with the lens enzyme and tissue-specific expression of two mRNAs.
复制标题
牛肾亮氨酸氨基肽酶 cDNA 的分离：与晶状体酶和两种 mRNA 的组织特异性表达的比较。
DOI：
10.1021/bi00087a006
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发表时间：
1993
期刊：
影响因子：
2.9
通讯作者：
Taylor,A
中科院分区：
文献类型：
--
作者：
Wallner,BP;Hession,C;Tizard,R;Frey,AZ;Zuliani,A;Mura,C;Jahngen-Hodge,J;Taylor,A
Revised Manuscript Received June 2, 1993® abstract: Aminopeptidases catalyze the hydrolysis of amino acid residues from the amino terminus of peptide substrates. Leucine aminopeptidase (LAP) from bovine lens is the best characterized aminopeptidase and the only LAP for which the amino acid sequence was determined by protein sequencing. Using this sequence information, we isolated a bovine kidney LAP cDNA and compared its deduced amino acid sequence tothe published amino acid sequence for bovine lens LAP. Overall, the sequences are highly conserved. However, several differences are observed. The kidney LAP cDNA indicates a 26 amino acid extension at the amino terminus which is not found in the mature purified lens LAP. The cDNA also indicates an additional octapeptide in the C-terminal region which was not indicated in the published lens LAP amino acid sequence but which was required for best fit of crystallographic data regarding bovine lens LAP. Several other single amino acid changes were also noted. Levels of LAP transcripts were examined in bovine lens and kidney tissue as well as in cultured lens cells. Lens epithelial tissue showed only one LAP transcript (2.4 kb) whereas two transcripts (2.0 and 2.4 kb) were observed in cultured lens cells derived from epithelial tissue and in kidney tissue. Using Northern blot analysis, we correlated LAP mRNA levels with previously determined changes of LAP activity in aging lens tissue and in progressively passaged lens epithelial cells which were used to simulate aging in vitro. No differences were found in LAP mRNA levels in epithelial tissue from old and young lenses. LAP mRNA concentrations are regulated in a manner consistent with the transient increases in LAP activity and inintracellular proteolytic activity in the progressively passaged cells. Northern blot analysis suggests that the 2.0-and 2.4-kb LAP transcripts arise by differential splicing of a common precursor RNA and that they code for similar but distinct proteins.Aminopeptidases constitute a large group of proteases which catalyze the hydrolysis of amino acid residues from the amino terminus of peptide substrates. They are widely distributed throughout the plant and animal kingdoms, and most have broad specificity. Aminopeptidases exist on cell surfaces, in soluble cytoplasmic forms, and several forms of these enzymes have been foundin many tissues or cells [Taylor et al., 1984a; Ledeme et al., 1983; Oettgen & Taylor, 1985; Watt & Yip,
