A bacteriophage-encoded J-domain protein interacts with the DnaK/Hsp70 chaperone and stabilizes the heat-shock factor σ32 of Escherichia coli.
A bacteriophage-encoded J-domain protein interacts with the DnaK/Hsp70 chaperone and stabilizes the heat-shock factor σ32 of Escherichia coli.
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DOI：
10.1371/journal.pgen.1003037
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发表时间：
2012
期刊：
影响因子：
4.5
通讯作者：
Genevaux P
中科院分区：
文献类型：
--
作者：
Perrody E;Cirinesi AM;Desplats C;Keppel F;Schwager F;Tranier S;Georgopoulos C;Genevaux P
普遍保守的J结构域蛋白（JDP）是Hsp 70（DnaK）伴侣的专性辅伴侣。它们刺激Hsp 70的ATP酶活性，促进底物递送，并赋予Hsp 70特异性细胞定位。在这项工作中，我们已经确定并表征了第一个由噬菌体编码的功能性JDP蛋白。具体而言，我们表明，T4相关的肠噬菌体RB 43的ORFan基因057 w编码一个真正的JDP蛋白，命名为Rki，它特异性地与大肠杆菌宿主多功能DnaK伴侣相互作用。然而，与E.在大肠杆菌中，Rki在体内或体外都不起一般辅伴侣的作用。单独表达Rki对野生型E.大肠杆菌，但在缺乏内源性DnaK或当Rki的保守J结构域突变时，毒性被消除。进一步的体内分析揭示，Rki在被RB 43感染后早期表达，并且rki基因的缺失显著损害RB 43增殖。此外，我们表明，在宿主dnaK基因的突变有效地抑制生长表型的RB 43 Rki缺失突变体，从而表明Rki特异性干扰DnaK细胞功能。最后，我们表明Rki与宿主DnaK分子伴侣的相互作用迅速导致热休克因子σ32的稳定，该因子通常是DnaK降解的目标。讨论了σ32的Rki依赖性稳定促进RB 43噬菌体增殖的机制。噬菌体是地球上最丰富的生物实体。因此，它们代表了最大的未开发遗传信息库。它们控制细菌生长，介导水平基因转移，从而对微生物生态和生长产生深远影响。噬菌体的一个显著特征是，它们编码许多迄今未知生物功能的开放阅读框架（称为ORFans），这些框架被称为我们生物圈的暗物质。在这里，我们已经广泛的特点，这样一个新的ORFan编码的蛋白质，Rki，编码的大型，有毒的肠杆菌科噬菌体RB 43。我们表明，Rki的功能，以控制宿主的应激反应在噬菌体感染的早期阶段，特别是通过与宿主DnaK/Hsp 70分子伴侣相互作用，以稳定主要的主机热休克因子，σ32。
The universally conserved J-domain proteins (JDPs) are obligate cochaperone partners of the Hsp70 (DnaK) chaperone. They stimulate Hsp70's ATPase activity, facilitate substrate delivery, and confer specific cellular localization to Hsp70. In this work, we have identified and characterized the first functional JDP protein encoded by a bacteriophage. Specifically, we show that the ORFan gene 057w of the T4-related enterobacteriophage RB43 encodes a bona fide JDP protein, named Rki, which specifically interacts with the Escherichia coli host multifunctional DnaK chaperone. However, in sharp contrast with the three known host JDP cochaperones of DnaK encoded by E. coli, Rki does not act as a generic cochaperone in vivo or in vitro. Expression of Rki alone is highly toxic for wild-type E. coli, but toxicity is abolished in the absence of endogenous DnaK or when the conserved J-domain of Rki is mutated. Further in vivo analyses revealed that Rki is expressed early after infection by RB43 and that deletion of the rki gene significantly impairs RB43 proliferation. Furthermore, we show that mutations in the host dnaK gene efficiently suppress the growth phenotype of the RB43 rki deletion mutant, thus indicating that Rki specifically interferes with DnaK cellular function. Finally, we show that the interaction of Rki with the host DnaK chaperone rapidly results in the stabilization of the heat-shock factor σ32, which is normally targeted for degradation by DnaK. The mechanism by which the Rki-dependent stabilization of σ32 facilitates RB43 bacteriophage proliferation is discussed. Bacteriophages are the most abundant biological entities on earth. As a consequence, they represent the largest reservoir of unexplored genetic information. They control bacterial growth, mediate horizontal gene transfer, and thus exert profound influence on microbial ecology and growth. One of the striking features of bacteriophages is that they code for many open reading frames of thus far unknown biological function (called ORFans), which have been referred to as the dark matter of our biosphere. Here we have extensively characterized such a novel ORFan-encoded protein, Rki, encoded by the large, virulent enterobacteriaceae bacteriophage RB43. We show that Rki functions to control the host stress-response during the early stages of bacteriophage infection, specifically by interacting with the host DnaK/Hsp70 chaperone to stabilize the major host heat-shock factor, σ32.
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DOI：
10.1073/pnas.0903503106
发表时间：
2009-05-26
影响因子：
11.1
作者：
Bertelsen, Eric B.;Chang, Lyra;Zuiderweg, Erik R. P.
通讯作者：
Zuiderweg, Erik R. P.
影响因子：
64.8
作者：
Glotzer, JB;Saltik, M;Cotten, M
通讯作者：
Cotten, M
影响因子：
8
作者：
Mayer, MP;Bukau, B
通讯作者：
Bukau, B
影响因子：
5.9
作者：
Hatfull, Graham F.;Hendrix, Roger W.
通讯作者：
Hendrix, Roger W.
影响因子：
16.8
作者：
Huang, P;Gautschi, M;Craig, EA
通讯作者：
Craig, EA