已入深夜,您辛苦了!由于当前在线用户较少,发布求助请尽量完整地填写文献信息,科研通机器人24小时在线,伴您度过漫漫科研夜!祝你早点完成任务,早点休息,好梦!

Mechanism of Recruitment and Activation of the Endosome-Associated Deubiquitinase AMSH

ESCRT公司 脱氮酶 泛素 内体 化学 细胞生物学 生物 生物化学 生物发生 基因 受体
作者
C. Davies,Lake N. Paul,Chittaranjan Das
出处
期刊:Biochemistry [American Chemical Society]
卷期号:52 (44): 7818-7829 被引量:36
标识
DOI:10.1021/bi401106b
摘要

AMSH, a deubiquitinating enzyme (DUB) with exquisite specificity for Lys63-linked polyubiquitin chains, is an endosome-associated DUB that regulates sorting of activated cell-surface signaling receptors to the lysosome, a process mediated by the members of the endosomal sorting complexes required for transport (ESCRT) machinery. Whole-exome sequencing of DNA samples from children with microcephaly capillary malformation (MIC-CAP) syndrome identified recessive mutations encoded in the AMSH gene causatively linked to the disease. Herein, we report a number of important observations that significantly advance our understanding of AMSH within the context of the ESCRT machinery. First, we performed mutational and kinetic analysis of the putative residues involved in diubiquitin recognition and catalysis with a view of better understanding the catalytic mechanism of AMSH. Our mutational and kinetic analysis reveals that recognition of the proximal ubiquitin is imperative for the linkage specificity and catalytic efficiency of the enzyme. The MIC-CAP disease mutation, Thr313Ile, yields a substantial loss of catalytic activity without any significant change in the thermodynamic stability of the protein, indicating that its perturbed catalytic activity is the basis of the disease. The catalytic activity of AMSH is stimulated upon binding to the ESCRT-0 member STAM; however, the precise mechanism and its significance are not known. On the basis of a number of biochemical and biophysical analyses, we are able to propose a model for activation according to which activation of AMSH is allowed by facile, simultaneous binding to two ubiquitin groups in a polyubiquitin substrate, one by the catalytic domain of the DUB (binding to the distal ubiquitin) and the other (the proximal ubiquitin) by the ubiquitin interacting motif (UIM) from STAM. Such a mode of binding would stabilize the ubiquitin chain in a productive orientation, resulting in an enhancement of the activity of the enzyme. These data together provide a mechanism for understanding the recruitment and activation of AMSH at ESCRT-0, providing biochemical and biophysical evidence that supports a role for AMSH when it is recruited to the initial ESCRT complex: it functions to facilitate the transfer of ubiquitinated receptors (cargo) from one ESCRT member to the next by disassembling the polyubiquitin chain while leaving some ubiquitin groups still attached to the cargo.
最长约 10秒,即可获得该文献文件

科研通智能强力驱动
Strongly Powered by AbleSci AI
更新
PDF的下载单位、IP信息已删除 (2025-6-4)

科研通是完全免费的文献互助平台,具备全网最快的应助速度,最高的求助完成率。 对每一个文献求助,科研通都将尽心尽力,给求助人一个满意的交代。
实时播报
L.C.完成签到,获得积分10
刚刚
刚刚
1秒前
千纸鹤完成签到 ,获得积分10
3秒前
4秒前
6秒前
充电宝应助甜蜜邑采纳,获得10
7秒前
100完成签到,获得积分10
10秒前
11秒前
HB完成签到,获得积分10
13秒前
怕黑的路人完成签到,获得积分10
15秒前
HH完成签到,获得积分10
16秒前
CipherSage应助蟹治猿采纳,获得10
18秒前
川荣李奈完成签到 ,获得积分10
19秒前
雪生在无人荒野完成签到,获得积分10
20秒前
动听的谷秋完成签到 ,获得积分10
20秒前
寒冷的青筠完成签到 ,获得积分10
21秒前
陈博士关注了科研通微信公众号
21秒前
朴实剑通完成签到,获得积分10
23秒前
火星上的柏柳完成签到 ,获得积分10
24秒前
luocan完成签到,获得积分10
25秒前
想法文章的菜鸟完成签到,获得积分10
26秒前
27秒前
星辰大海应助科研通管家采纳,获得10
28秒前
桐桐应助科研通管家采纳,获得10
28秒前
JamesPei应助科研通管家采纳,获得10
28秒前
风清扬完成签到,获得积分10
28秒前
28秒前
科研通AI2S应助科研通管家采纳,获得10
28秒前
小马甲应助科研通管家采纳,获得10
28秒前
28秒前
储物间完成签到,获得积分10
28秒前
非了个凡完成签到 ,获得积分10
31秒前
32秒前
秀丽奎完成签到 ,获得积分10
34秒前
充电宝应助HH采纳,获得10
36秒前
KONOHA完成签到,获得积分10
37秒前
橙子完成签到,获得积分10
37秒前
花深粥发布了新的文献求助10
37秒前
每文完成签到,获得积分10
38秒前
高分求助中
(应助此贴封号)【重要!!请各用户(尤其是新用户)详细阅读】【科研通的精品贴汇总】 10000
Comprehensive Methanol Science Production, Applications, and Emerging Technologies 1200
Architectural Corrosion and Critical Infrastructure 1000
Early Devonian echinoderms from Victoria (Rhombifera, Blastoidea and Ophiocistioidea) 1000
By R. Scott Kretchmar - Practical Philosophy of Sport and Physical Activity - 2nd (second) Edition: 2nd (second) Edition 666
Electrochemistry: Volume 17 600
Physical Chemistry: How Chemistry Works 500
热门求助领域 (近24小时)
化学 医学 生物 材料科学 工程类 有机化学 内科学 生物化学 物理 计算机科学 纳米技术 遗传学 基因 复合材料 化学工程 物理化学 病理 催化作用 免疫学 量子力学
热门帖子
关注 科研通微信公众号,转发送积分 4944455
求助须知:如何正确求助?哪些是违规求助? 4209377
关于积分的说明 13085135
捐赠科研通 3989004
什么是DOI,文献DOI怎么找? 2183965
邀请新用户注册赠送积分活动 1199322
关于科研通互助平台的介绍 1112234