A conserved region in the tail domain of vimentin is involved in its assembly into intermediate filaments.
A conserved region in the tail domain of vimentin is involved in its assembly into intermediate filaments.
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波形蛋白尾部结构域中的一个保守区域参与其组装成中间丝。
DOI：
10.1002/cm.970280309
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发表时间：
1994
影响因子：
--
通讯作者：
Ip,W
中科院分区：
文献类型：
--
作者：
Makarova,I;Carpenter,D;Khan,S;Ip,W
虽然已知中间丝蛋白的头部和杆结构域在丝组装中起重要作用，但尾结构域在该功能中的作用尚不清楚，现有信息支持相互矛盾的结论。我们通过比较将相同的cDNA构建（编码带有修饰尾结构域的蛋白）转染到含有和不含有内源性IF蛋白的细胞系中来研究这个问题。通过这种方法，我们能够区分突变IF蛋白启动重新组装的能力，以及与现有纤维网络结合的能力。在表达vimentin （vim+）的细胞中，在一个高度保守的三肽arg - asp - gly （RDG）上或其附近进行修饰的vimentin可以整合到现有的IF网络中，但在不表达IF蛋白（vim -）的细胞中则不具备组装能力。通过重新引入野生型vimentin cDNA， RDG突变型vimentin在vim细胞中组装成丝阵列的失败是可逆的，因此野生型和突变型vimentin共同组装成一个相同的IF网络。我们得出结论，III型IF蛋白的尾部结构域，可能是角蛋白K8和K18，在IF组装中的功能与其他结构域不同；包含RDG三肽的区域似乎在组装过程中很重要。©1994 Wiley‐Liss, Inc。
Although the head and rod domains of intermediate filament (IF) proteins are known to play significant roles in filament assembly, the role of the tail domain in this function is unclear and the available information supports contradictory conclusions. We examined this question by comparing transfection of the same cDNA constructs, encoding vimentins with modified tail domains, into cell lines that do and do not contain endogenous IF proteins. By this approach, we were able to distinguish between the ability of a mutant IF protein to initiate assembly de novo, from that of incorporating into existing filament networks. Vimentins with modifications at or near a highly conserved tripeptide, arg‐asp‐gly (RDG), of the tail domain incorporated into existing IF networks in vimentin‐expressing (vim+) cells, but were assembly‐incompetent in cells that did not express IF proteins (vim−). The failure of the RDG mutant vimentins to assemble into filament arrays in vim‐cells was reversible by re‐introducing a wild‐type vimentin cDNA, whereupon both wild‐type and mutant vimentins coassembled into one and the same IF network. We conclude that the function of the tail domain of type III IF proteins, and possibly of keratins K8 and K18, in IF assembly is distinct from those of other domains; a region encompassing the RDG tripeptide appears to be important in the assembly process. © 1994 Wiley‐Liss, Inc.