- 期刊
核糖核酸水解酵素A家族之生化特性與生理功能
Biochemical Characterization and Physiological Function of the Ribonuclease A Superfamily
摘要
核糖核酸水解酵素(ribonuclease, RNase)為代謝核糖核酸(ribonucleic acid, RNA)、調控基因表現之重要蛋自質，廣泛存在於生物體內。RNase依其序列相似性可歸類為不同家族，而RNase A家族為其中之一。目前發現Rase A家族成員僅表現於脊椎動物，且在演化過程中，不同物種間皆其有高度之基因保留性，因此RNaseA家族對於了解脊椎動物專一表現蛋白質之生物化學、蛋白質結構與演化上皆佔有重要地位。RNaseA家族成員包含RNase1、嗜酸性白血球相關之RNA水解酵素家族(eosinophil-associated RNase family, EAR family)以及RNase4至RNase13。這些基因在轉錄轉譯後所產生多肽鏈(polypeptide chain)，需經修飾作用後，始形成成熟蛋白質。此家族成員對RNA受質，具有嘧啶(pyrimidine)專一結合位置，且除了水解RNA之酵素活性外，不同家族成員亦有抑繭或促進血管外成等功能。由於在不同組織器官之表現程度不同，對於調控動物之生理具重要地位。
並列摘要
Ribonucleases (RNases) are found ubiquitously in living organisms and involved in ribonucleic acid (RNA) metabolism, which play an important role in regulation of gene expression. According to the similarity of amino acid sequences, there are several different RNase families including RNase A superfamily. The members of RNase A superfamily are expressed exclusively in vertebrates and these evolving proteins show highly conserved sequences among species Therefore, the vertebrate-specific RNase A family is an important source for the studies of protein biochemistry, structures, and evolution. The RNase 4 superfamily enzymes, including RNase 1, eosinophil-associated RNase family and RNase 4 to RNase 13 are synthesized as premature proteins, which are posttranslationally modified to become mature proteins. In addition to the catalytic activity toward RNAs with pyrmidine preference on the B1 biding site, it has been demonstrated that the RNase A superfamily enzymes possess multiple physiological functions in different tissues with various expression levels, implying the important biological roles of RNase A family on the physiological regulation.