TISSUE-SPECIFIC EXPRESSION OF MOUSE ALPHA-AMYLASE GENES - NUCLEOTIDE-SEQUENCE OF ISOENZYME MESSENGER-RNAS FROM PANCREAS AND SALIVARY-GLAND
TISSUE-SPECIFIC EXPRESSION OF MOUSE ALPHA-AMYLASE GENES - NUCLEOTIDE-SEQUENCE OF ISOENZYME MESSENGER-RNAS FROM PANCREAS AND SALIVARY-GLAND
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DOI：
10.1016/0092-8674(80)90125-7
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发表时间：
1980-01-01
期刊：
影响因子：
64.5
通讯作者：
YOUNG, RA
中科院分区：
文献类型：
--
作者：
HAGENBUCHLE, O;BOVEY, R;YOUNG, RA
测定了两种不同的小鼠α-淀粉酶基因的核苷酸序列，其中一种在胰腺中发现，另一种在唾液腺中发现。分别来自胰腺和唾液腺的1577和1659个核苷酸mRNA物种是每个组织中积累的主要α-淀粉酶物种。MRNA长度的差异主要存在于5‘’非编码区。这些mRNAs的可比部分有89%的同源性。NRNA序列预测508和511个氨基酸残基的α-淀粉酶前体蛋白，几乎占整个mRNA的编码量；蛋白质长度的差异是由于唾液腺mRNA的翻译部分存在9个核苷酸片段，而不是胰腺。预测的蛋白质的长度和氨基酸组成与其他人的经验确定的一致。这些蛋白质的氨基酸序列不同12%，这解释了之前观察到的净电荷和抗原性的差异。唾液腺α-淀粉酶mRNA的翻译不是在最靠近5‘’末端的AUG密码子开始的，因为该密码子之后几乎立即是终止三联体UAA。这一观察结果可能对真核生物的翻译启动机制有一定的启示。
The nucleotide sequence of 2 different mouse .alpha.-amylase mRNA species, one found in the pancreas and the other in the salivary gland, were determined. The 1577 and 1659 nucleotide mRNA species from pancreas and salivary gland, respectively, are the major .alpha.-amylase species which accumulate in each tissue. Differences in mRNA length are primarily in the 5'' noncoding regions. Comparable portions of the mRNAs are 89% homologous. The nRNA sequences predict .alpha.-amylase precursor proteins of 508 and 511 amino acid residues, accounting for nearly the entire coding capacity of the mRNA; differences in protein length occur as a result of a 9 nucleotide segment present within the translated portion of salivary gland, but not pancreas, mRNA. The lengths and amino acid compositions of the predicted proteins concur with those determined empirically by others. These proteins differ 12% in amino acid sequence, explaining previously observed differences in net charge and antigenic properties. Translation of the salivary gland .alpha.-amylase mRNA is not initiated at the AUG codon nearest the 5'' terminus since that codon is almost immediately followed by the termination triplet UAA. This observation may have implications for the mechanism of translation initiation in eukaroytes.