Translation Regulation and RNA Granule Formation after Heat Shock of Procyclic Form Trypanosoma brucei: Many Heat-Induced mRNAs Are also Increased during Differentiation to Mammalian-Infective Forms.
Translation Regulation and RNA Granule Formation after Heat Shock of Procyclic Form Trypanosoma brucei: Many Heat-Induced mRNAs Are also Increased during Differentiation to Mammalian-Infective Forms.
复制标题
Procyclic形成锥虫的热休克后的翻译调节和RNA颗粒形成：在分化为哺乳动物感染形式的过程中，许多热诱导的mRNA也增加。
DOI：
10.1371/journal.pntd.0004982
复制
发表时间：
2016-09
影响因子：
3.8
通讯作者：
Clayton C
中科院分区：
文献类型：
--
作者：
Minia I;Merce C;Terrao M;Clayton C
非洲锥虫原环型在采采蝇的中肠中繁殖，通常在27°C下培养。37°C及以上的热休克导致翻译的普遍抑制，严重的热休克（41°C）导致mRNA在颗粒中被隔离。由锌指蛋白ZC3H11结合的mrna，包括那些编码重折叠伴侣的mrna，可以逃脱热诱导的翻译抑制。在27°C时，ZC3H11 mRNA主要以未翻译的细胞质信使核糖核蛋白颗粒的形式存在，但在37°C - 41°C的热冲击后，ZC3H11 mRNA进入多体部分。为了研究热休克翻译调控和颗粒形成的范围和特异性，我们分析了27°C和39°C 1小时后多体上mRNA的分布，以及41°C热休克颗粒的mRNA含量。我们发现，与ZC3H11结合的mrna在39°C时保留在多体中，在41°C时不被隔离在颗粒中。正如之前在饥饿应激颗粒中看到的那样，编码核糖体蛋白的mrna被排除在热休克颗粒中。39℃热休克后，70个mrna向多体部分移动，260个mrna相对丰度增加。令人惊讶的是，当锥虫迁移到舌蝇唾液腺时，这些mrna中的许多也会增加。因此，在野生环境中，由于昼夜变化和定期摄入温血而引起的温度变化可能会影响原循环形式向哺乳动物感染形式发展的效率。当锥虫在采采蝇体内时，由于昼夜变化和周期性摄入温血，它们必须应对从低于20°C到37°C的温度变化。在实验室中，原环型（在中肠中繁殖的形式）通常在27°C下培养。当原环形式被加热到37°C或更高的温度时，它们会减少蛋白质的产生，并且在41°C时，mrna聚集成颗粒。我们在这里表明，相当多的mrna不包括在颗粒中，并继续用于制造蛋白质。为了保护细胞免受热休克的影响，需要继续制造一些蛋白质。然而，有趣的是，适度的热休克刺激了寄生虫进一步发育成可以在唾液腺定居的形式所需的基因的表达。因此，在野外，温度变化可能会影响采采蝇体内锥虫感染哺乳动物的效率。
African trypanosome procyclic forms multiply in the midgut of tsetse flies, and are routinely cultured at 27°C. Heat shocks of 37°C and above result in general inhibition of translation, and severe heat shock (41°C) results in sequestration of mRNA in granules. The mRNAs that are bound by the zinc-finger protein ZC3H11, including those encoding refolding chaperones, escape heat-induced translation inhibition. At 27°C, ZC3H11 mRNA is predominantly present as an untranslated cytosolic messenger ribonucleoprotein particle, but after heat shocks of 37°C—41°C, the ZC3H11 mRNA moves into the polysomal fraction. To investigate the scope and specificities of heat-shock translational regulation and granule formation, we analysed the distributions of mRNAs on polysomes at 27°C and after 1 hour at 39°C, and the mRNA content of 41°C heat shock granules. We found that mRNAs that bind to ZC3H11 remained in polysomes at 39°C and were protected from sequestration in granules at 41°C. As previously seen for starvation stress granules, the mRNAs that encode ribosomal proteins were excluded from heat-shock granules. 70 mRNAs moved towards the polysomal fraction after the 39°C heat shock, and 260 increased in relative abundance. Surprisingly, many of these mRNAs are also increased when trypanosomes migrate to the tsetse salivary glands. It therefore seems possible that in the wild, temperature changes due to diurnal variations and periodic intake of warm blood might influence the efficiency with which procyclic forms develop into mammalian-infective forms. When trypanosomes are inside tsetse flies, they have to cope with temperature variations from below 20°C up to 37°C, due to diurnal variations and periodic intake of warm blood. In the laboratory, procyclic forms (the form that multiplies in the midgut), are routinely cultured at 27°C. When procyclic forms are heated to temperatures of 37°C and above, they decrease protein production, and at 41°C, mRNAs aggregate into granules. We show here that quite a large number of mRNAs are not included in granules and continue to be used for making proteins. Some of the proteins that continue to be made are needed in order to defend the cells against the effects of heat shock. Interestingly, however, a moderate heat shock stimulates expression of genes needed for the parasites to develop further into forms that can colonise the salivary glands. It thus seems possible that in the field, temperature variations might influence the efficiency with which of trypanosomes in tsetse flies become infective for mammals.
登录
查看更多内容
DOI：
10.1083/jcb.201506114
发表时间：
2015-10-26
期刊：
The Journal of cell biology
影响因子：
--
作者：
Domingo-Sananes MR;Szöőr B;Ferguson MA;Urbaniak MD;Matthews KR
通讯作者：
Matthews KR
影响因子：
4.4
作者：
Antwi EB;Haanstra JR;Ramasamy G;Jensen B;Droll D;Rojas F;Minia I;Terrao M;Mercé C;Matthews K;Myler PJ;Parsons M;Clayton C
通讯作者：
Clayton C
影响因子：
14.9
作者：
Fritz M;Vanselow J;Sauer N;Lamer S;Goos C;Siegel TN;Subota I;Schlosser A;Carrington M;Kramer S
通讯作者：
Kramer S
影响因子：
56.9
作者：
Kolev, Nikolay G.;Ramey-Butler, Kiantra;Tschudi, Christian
通讯作者：
Tschudi, Christian
影响因子：
3.3
作者：
Krüger T;Hofweber M;Kramer S
通讯作者：
Kramer S