A dual function for chaperones SSB-RAC and the NAC nascent polypeptide-associated complex on ribosomes.
A dual function for chaperones SSB-RAC and the NAC nascent polypeptide-associated complex on ribosomes.
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DOI：
10.1083/jcb.200910074
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发表时间：
2010-04-05
期刊：
影响因子：
--
通讯作者：
Deuerling E
中科院分区：
文献类型：
--
作者：
Koplin A;Preissler S;Ilina Y;Koch M;Scior A;Erhardt M;Deuerling E
除了协助蛋白质折叠，SSB和NAC还调节核糖体的生物发生(另见Albanèse等人的配对论文。在本期中)。酵母Hsp70/40系统SSB-RAC(应力70B-核糖体相关复合体)与核糖体结合，并与新生多肽接触以帮助共翻译折叠。在这项研究中，我们证明了新生多肽相关复合体(NAC)，另一个核糖体拴系系统，在功能上与SSB-RAC和胞浆Hsp70网络相连。同时删除编码NAC和SSB的基因会导致在蛋白质折叠应激条件下细胞活力的条件性丧失。此外，NAC突变显示了与Sse1的遗传相互作用，Sse1是一种调节胞质Hsp70网络的核苷酸交换因子。缺乏SSB或Sse1的细胞显示出蛋白质聚集，这可以通过额外的NAC丢失来增强；然而，这些突变体在其潜在的客户谱系上有所不同。核糖体蛋白和生物发生因子的聚集伴随着核糖体颗粒和翻译核糖体的明显缺陷，仅在SSbΔ和NacΔSSbΔ细胞中发生，表明SSb和Nac控制核糖体的生物发生。因此，SSB-RAC和NAC帮助蛋白质折叠，同样具有调节核糖体水平的重要功能。这些发现强调了核糖体生产与核糖体相关伴侣蛋白折叠能力相协调的概念。
In addition to assisting with protein folding, SSB and NAC also regulate ribosome biogenesis (see also companion paper from Albanèse et al. in this issue). The yeast Hsp70/40 system SSB–RAC (stress 70 B–ribosome-associated complex) binds to ribosomes and contacts nascent polypeptides to assist cotranslational folding. In this study, we demonstrate that nascent polypeptide–associated complex (NAC), another ribosome-tethered system, is functionally connected to SSB–RAC and the cytosolic Hsp70 network. Simultaneous deletions of genes encoding NAC and SSB caused conditional loss of cell viability under protein-folding stress conditions. Furthermore, NAC mutations revealed genetic interaction with a deletion of Sse1, a nucleotide exchange factor regulating the cytosolic Hsp70 network. Cells lacking SSB or Sse1 showed protein aggregation, which is enhanced by additional loss of NAC; however, these mutants differ in their potential client repertoire. Aggregation of ribosomal proteins and biogenesis factors accompanied by a pronounced deficiency in ribosomal particles and translating ribosomes only occurs in ssbΔ and nacΔssbΔ cells, suggesting that SSB and NAC control ribosome biogenesis. Thus, SSB–RAC and NAC assist protein folding and likewise have important functions for regulation of ribosome levels. These findings emphasize the concept that ribosome production is coordinated with the protein-folding capacity of ribosome-associated chaperones.
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影响因子：
56.9
作者：
Hundley, HA;Walter, W;Craig, EA
通讯作者：
Craig, EA
影响因子：
64.5
作者：
Martinez-Hackert E;Hendrickson WA
通讯作者：
Hendrickson WA
影响因子：
11.4
作者：
Pfund, C;Lopez-Hoyo, N;Craig, EA
通讯作者：
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影响因子：
9.2
作者：
Powers, T;Walter, P
通讯作者：
Walter, P
DOI：
10.1083/jcb.144.3.389
发表时间：
1999-02-08
期刊：
The Journal of cell biology
影响因子：
--
作者：
Hurt E;Hannus S;Schmelzl B;Lau D;Tollervey D;Simos G
通讯作者：
Simos G