Six mouse alpha-tubulin mRNAs encode five distinct isotypes: testis-specific expression of two sister genes
Six mouse alpha-tubulin mRNAs encode five distinct isotypes: testis-specific expression of two sister genes
复制标题
六种小鼠 α-微管蛋白 mRNA 编码五种不同的同种型：两个姐妹基因的睾丸特异性表达
DOI：
10.1128/mcb.6.7.2409-2419.1986
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发表时间：
1986
影响因子：
5.3
通讯作者：
N. Cowan
中科院分区：
文献类型：
--
作者：
A. Villasanté;D. Wang;P. Dobner;P. Dolph;S. Lewis;N. Cowan
描述了五种小鼠α-微管蛋白同种型，每种同种型的区别在于编码区内存在独特的氨基酸取代。大多数，但不是所有的这些同种型特异性氨基酸，在羧基末端聚集。所述α-微管蛋白同种型之一仅在睾丸中表达，并由两个密切相关的基因（M α 3和M α 7）编码，这两个基因具有同源的3'非翻译区，但在多个第三密码子位置和它们的5'非翻译区不同。我们发现，编码相同的睾丸特异性同种型的α-微管蛋白基因的一个亚家族也存在于人类中。因此，我们得出结论，导致一对基因编码睾丸特异性α-微管蛋白同种型的重复事件早于哺乳动物辐射，并且重复序列的两个成员自物种分化以来一直保持不变。第二个α-微管蛋白基因M α 6以低水平普遍表达，而第三个基因M α 4是独特的，因为它不编码羧基末端酪氨酸残基。该基因产生两种转录物：肌肉中丰富的1.8 kb mRNA和睾丸中丰富的2.4 kb mRNA。而1.8-kb的mRNA编码一个独特的α-微管蛋白同种型，2.4-kb的mRNA是有缺陷的，因为翻译起始所需的甲硫氨酸残基丢失。各种α-微管蛋白同种型的发育表达模式。我们的数据支持这样的观点，即个别微管蛋白同种型能够赋予不同种类的微管功能特异性。
Five mouse alpha-tubulin isotypes are described, each distinguished by the presence of unique amino acid substitutions within the coding region. Most, though not all of these isotype-specific amino acids, are clustered at the carboxy terminus. One of the alpha-tubulin isotypes described is expressed exclusively in testis and is encoded by two closely related genes (M alpha 3 and M alpha 7) which have homologous 3' untranslated regions but which differ at multiple third codon positions and in their 5' untranslated regions. We show that a subfamily of alpha-tubulin genes encoding the same testis-specific isotype also exists in humans. Thus, we conclude that the duplication event leading to a pair of genes encoding a testis-specific alpha-tubulin isotype predated the mammalian radiation, and both members of the duplicated sequence have been maintained since species divergence. A second alpha-tubulin gene, M alpha 6, is expressed ubiquitously at a low level, whereas a third gene, M alpha 4, is unique in that it does not encode a carboxy-terminal tyrosine residue. This gene yields two transcripts: a 1.8-kilobase (kb) mRNA that is abundant in muscle and a 2.4-kb mRNA that is abundant in testis. Whereas the 1.8-kb mRNA encodes a distinct alpha-tubulin isotype, the 2.4-kb mRNA is defective in that the methionine residue required for translational initiation is missing. Patterns of developmental expression of the various alpha-tubulin isotypes are presented. Our data support the view that individual tubulin isotypes are capable of conferring functional specificity on different kinds of microtubules.
DOI：
10.1073/pnas.80.5.1194
发表时间：
1983-01-01
期刊：
PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA-BIOLOGICAL SCIENCES
影响因子：
--
作者：
YOUNG, RA;DAVIS, RW
通讯作者：
DAVIS, RW