Yeast prions and Hsp70 co-chaperones

酵母朊病毒和 Hsp70 共伴侣

• 批准号: 8553388
• 负责人: Daniel Masison
• 金额: $ 26.09万
• 依托单位: NATIONAL INSTITUTE OF DIABETES AND DIGESTIVE AND KIDNEY DISEASES
• 依托单位国家: 美国
• 资助国家: 美国
• 起止时间: 至
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/8553388
• 关键词: Affect; Alleles; Amyloid; Cell physiology; Cells; Data; Escherichia coli; Family; Goals; Guanine Nucleotide Exchange Factors; Life; Mediating; Molecular Chaperones; Nucleotides; Play; Prions; Process; Protein Isoforms; Proteins; Reaction; Regulation; Role; Specificity; System; Tertiary Protein Structure; Yeasts; chaperone machinery; insight; mutant; non-prion; overexpression; preference; yeast prion

Earlier we showed altered expression of Hsp40s, nucleotide exchange factors (NEFs) and tetratricopeptide repeat (TPR) domain proteins affect prion propagation in wild type and Hsp70 mutant cells. We also identified several Hsp40 and TPR protein mutant alleles that impair or enhance prion propagation. Our data suggest that many, if not all, of the observed effects of co-chaperones on prions are mediated by their regulation of Hsp70 activities. In many instances the same conditions producing a significant effect on one prion have either little or an opposite effect on a different prion. These data point to a prion preference or specificity of the Hsp70/co-chaperone pairings. Targeting the two major yeast Hsp40s (Ydj1p and Sis1p), we earlier showed that while overexpressing Sis1p has no effect on prions, elimination of the URE3 prion by overproduced Ydj1p requires only its ability to regulate Hsp70. The curing efficiency also depended on particular isoforms of Hsp70. Therefore, prion "curing" was indirect and required interaction of specific Hsp40 with Hsp70, but not amyloid. Our other data show that while Hsp40s other than Sis1p can contribute to the prion replication mechanism, curing of prions by overexpressed Hsp104 is strictly dependent on Sis1p. These findings are consistent with prion propagation and elimination requiring different chaperone activities, and suggest specificity of Hsp104 functions can be controlled by the way Hsp70 interacts with its co-chaperones. We adapted our yeast system for studying prokaryotic chaperones and co-chaperones to determine whether various functions of chaperone machinery components are specific or overlapping. We found ClpB supports both prion propagation and thermotolerance in yeast if it is modified to interact with yeast Hsp70 or if E. coli Hsp70 and its cognate nucleotide exchange factor (NEF) are present. Different yeast Hsp40s play critical roles in these distinct processes. Our findings show prion propagation and thermotolerance minimally require Hsp100, Hsp70, NEF and Hsp40, with Hsp40 directing functions of this machinery. They also define cooperative interactions among these components that are specific or interchangeable across life kingdoms, and imply Hsp100 family disaggregases possess intrinsic amyloid remodeling activity.

早些时候，我们显示了HSP40S，核苷酸交换因子（NEF）和四肽重复（TPR）结构域蛋白的表达改变，会影响野生型和HSP70突变细胞中的prion传播。我们还确定了损害或增强prion传播的几个HSP40和TPR蛋白突变等位基因。我们的数据表明，许多（如果不是全部）共同伴侣对王室的影响是通过其对HSP70活动的调节来介导的。在许多情况下，相同的条件会对一个prion产生重大影响，对不同的prion几乎没有影响或相反的影响。这些数据指向HSP70/co-Chaperone配对的prion偏爱或特异性。 针对两个主要的酵母HSP40（YDJ1P和SIS1P），我们早些时候表明，尽管过表达SIS1P对Prions没有影响，但通过过量生产的YDJ1P消除URE3 prion只需要其调节HSP70的能力。固化效率还取决于HSP70的特定同工型。因此，Prion“固化”是间接的，并且需要特定的HSP40与HSP70的相互作用，但不是淀粉样蛋白。我们的其他数据表明，尽管SIS1P以外的HSP40S可以有助于prion复制机制，但过表达HSP104的prions固化严格取决于SIS1P。这些发现与需要不同的伴侣活动的prion传播和消除相一致，并建议可以通过HSP70与其共伴侣相互作用的方式来控制HSP104功能的特异性。 我们调整了酵母系统，用于研究原核生物伴侣和副酮，以确定伴侣机械组件的各种功能是特定的还是重叠的。我们发现，如果对酵母进行了修改以与酵母HSP70相互作用，或者存在大肠杆菌HSP70及其同源核苷酸交换因子（NEF），则CLPB支持酵母中的prion传播和耐热性。不同的酵母HSP40在这些不同的过程中起着关键作用。我们的发现显示了该机械的HSP40指导功能，显示了最小的HSP100，HSP70，NEF和HSP40的prion传播和耐热性。他们还定义了这些组成部分之间特定或可以互换王国的合作相互作用，这意味着HSP100家族分裂酶具有固有的淀粉样蛋白重塑活性。