四膜虫中编码两种钾离子通道亚型的基因内部消除序列的比较。

A comparison of internal eliminated sequences in the genes that encode two K(+)-channel isoforms in Paramecium tetraurelia.

作者信息

Ling K Y, Vaillant B, Haynes W J, Saimi Y, Kung C

机构信息

Laboratory of Molecular Biology, University of Wisconsin, Madison 53706, USA.

出版信息

J Eukaryot Microbiol. 1998 Jul-Aug;45(4):459-65. doi: 10.1111/j.1550-7408.1998.tb05100.x.

DOI:10.1111/j.1550-7408.1998.tb05100.x

PMID:9703683

Abstract

We examined both the somatic (macro-) and the germinal (micronuclear) DNAs that encode two K(+)-channel isoforms, PAK1 and PAK11, in Paramecium tetraurelia. The coding regions of these two isoforms are 88% identical in nucleotides and 95% identical in amino acids. Their introns are also highly conserved. Even some of the internal eliminated sequences in PAK1 and PAK11 are clearly related. PAK1 has five IESs; PAK11 has four. The first (5'-most) IESs of the two genes are located at the same site in the coding sequence but differ in size. The 2nd IES in PAK1 (206-bp), the largest among the nine IESs, has no PAK11 counterpart. The 3rd, 4th and 5th IESs in PAK1 have a counterpart in PAK11 that is similar in size and in sequence, and identical in its position in the coding sequence. In addition, the first IES of PAK11 bears some resemblance to the 4th one of PAK1. The similarities and differences between the two sets of IESs are discussed with respect to the origin and divergence of the two K(+)-channel isoforms.

摘要

我们研究了编码草履虫（双小核草履虫）中两种钾离子通道亚型PAK1和PAK11的体细胞（宏观）DNA和生殖细胞（微核）DNA。这两种亚型的编码区在核苷酸上有88%的同一性，在氨基酸上有95%的同一性。它们的内含子也高度保守。甚至PAK1和PAK11中的一些内部消除序列也明显相关。PAK1有五个内部消除序列（IESs）；PAK11有四个。这两个基因的第一个（最5'端）IESs位于编码序列的同一位置，但大小不同。PAK1中的第二个IES（206碱基对），是九个IESs中最大的，没有PAK11的对应序列。PAK1中的第三、第四和第五个IESs在PAK11中有一个对应序列，其大小和序列相似，在编码序列中的位置相同。此外，PAK11的第一个IES与PAK1的第四个IES有一些相似之处。针对这两种钾离子通道亚型的起源和分化，讨论了两组IESs之间的异同。