Small glutamine-rich tetratricopeptide repeat-containing protein is composed of three structural units with distinct functions
Small glutamine-rich tetratricopeptide repeat-containing protein is composed of three structural units with distinct functions
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DOI：
10.1016/j.abb.2004.12.020
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发表时间：
2005-03-15
影响因子：
3.9
通讯作者：
Wang, C
中科院分区：
文献类型：
--
作者：
Liou, ST;Wang, C
此前，我们确定了人类富含谷氨酰胺的小四肽重复序列蛋白（SGT）作为共伴侣。 SGT 中的四肽重复 (TPR) 结构域负责与 Hsc70 相互作用。在这项研究中，我们证明了 SGT 的 TPR 结构域也与 Hsp90 相互作用。此外，我们研究了 TPR 结构域之外的 SGT 区域的功能意义。显然，SGT 的 N 端结构域对于其自缔合是必要且充分的；并且，SGT可以是形状拉长的二聚体。 C 端富含谷氨酰胺的反离子能够与由连续非极性氨基酸组成的短肽片段相互作用。 SGT 的 C 末端片段确实在 SGT 与体外翻译的大鼠 1 型葡萄糖转运蛋白（一种在非生理状态下折叠的完整膜蛋白）的关联中发挥着重要作用。此外，在 SGT 存在的情况下，网织红细胞裂解物中转运蛋白的降解受到抑制。综上所述，SGT可分为三个具有不同功能的结构单元。 (C) 2004 Elsevier Inc. 保留所有权利。
Previously, we identified the human small glutamine-rich tetratricopeptide repeat-containing protein (SGT) as a co-chaperone. The tetratricopeptide repeat (TPR) domain in SGT is responsible for interacting with Hsc70. In this Study, we demonstrated that the TPR domain of SGT also interacted with Hsp90. Moreover, we investigated the functional significance of regions of SGT outside the TPR domain. Evidently, the N-terminal domain of SGT is necessary and sufficient for its self-association; and, SGT may be a dimer elongated in shape. The C-terminal glutamine-rich re ion has the capacity to interact with short peptide segments composed of consecutive non-polar amino acids. The C-terminal fragment of SGT indeed plays a role ill the association of SGT with in vitro translated rat type 1 glucose transporter, an integral membrane protein folded in a non-physiological state. Moreover, in the presence of SGT, the degradation of the transporter in reticulocyte lysates is inhibited. Taking together, SGT can be separated into three structural units with distinct functions. (C) 2004 Elsevier Inc. All rights reserved.