• 【来自担子菌Ustilago maydis的RIM101 / pacC同源物在多种pH敏感现象中起作用。】 复制标题 收藏 收藏
    DOI:10.1128/EC.4.6.999-1008.2005 复制DOI
    作者列表:Aréchiga-Carvajal ET,Ruiz-Herrera J
    BACKGROUND & AIMS: :A homologue of the gene encoding the transcription factor Rim101 (PacC), involved in pH signal transduction in fungi, was identified in the pathogenic basidiomycete Ustilago maydis. The gene (RIM101) encodes a protein of 827 amino acid residues, which shows highest similarity to PacC proteins from Fusarium oxysporum and Aspergillus niger. The gene had the capacity to restore protease activity to rim101 mutants from Yarrowia lipolytica, confirming its homologous function, and was expressed at both acid and neutral pH. Null Deltarim101 mutants were not affected in the in vitro pH-induced dimorphic transition, their growth rate, resistance to hypertonic sorbitol or KCl stress, and pathogenicity. However, similar to pacC (rim101) mutants in other fungi, they displayed a pleiotropic phenotype with alterations in morphogenesis, impairment in protease secretion, and increased sensitivity to Na+ and Li+ ions. Other phenotypic characteristics not previously reported in fungal pacC (rim101) mutants (morphological changes, increased sensitivity to lytic enzymes, and augmented polysaccharide secretion) were also observed in U. maydis mutants. All these modifications were alleviated by transformation with the wild-type gene, confirming that all were the result of mutation in RIM101. These data indicate that the Pal/Rim pathway is functional in U. maydis (and probably in other basidiomycetes) and plays complex roles in pH-sensing phenomena, as occurs in ascomycetes and deuteromycetes.
    背景与目标: :在致病性担子菌Ustilago maydis中鉴定到了编码真菌中pH信号转导的转录因子Rim101(PacC)的基因的同源物。该基因(RIM101)编码一个827个氨基酸残基的蛋白质,与尖酸镰刀菌和黑曲霉的PacC蛋白显示出最高的相似性。该基因具有恢复来自解脂耶氏酵母的rim101突变体的蛋白酶活性的能力,证实了其同源功能,并且在酸性和中性pH下均表达。 Null Deltarim101突变体在体外pH诱导的双态转化,其生长速率,对高渗山梨糖醇或KCl胁迫的抗性以及致病性方面均不受影响。但是,类似于其他真菌中的pacC(rim101)突变体,它们表现出多效性表型,其形态发生改变,蛋白酶分泌受损,并且对Na和Li离子的敏感性增加。在U. maydis突变体中还观察到了真菌pacC(rim101)突变体中以前未报道的其他表型特征(形态变化,对裂解酶的敏感性增加和多糖分泌增加)。通过用野生型基因转化减轻了所有这些修饰,证实了所有这些修饰都是RIM101中突变的结果。这些数据表明,Pal / Rim途径在马氏假单胞菌(可能还有其他担子菌)中起作用,并且在pH感测现象中起着复杂的作用,如在子囊菌和氘代菌中的情况。
  • 【RIM101信号转导途径可调节实验性角质病期间的白色念珠菌毒力。】 复制标题 收藏 收藏
    DOI:10.1167/iovs.09-4726 复制DOI
    作者列表:Yuan X,Mitchell BM,Hua X,Davis DA,Wilhelmus KR
    BACKGROUND & AIMS: PURPOSE:To examine the role of the fungal RIM101 signal transduction pathway in the pathogenesis of Candida albicans keratitis. METHODS:C. albicans wild-type strain SC5314, prototrophic mutant control DAY185, and homozygous fungal mutants for the rim8, rim13, rim20, rim101, and phr1 genes were evaluated in vitro using proliferation and filamentation assays. Scarified corneas of BALB/c and C57BL/6J mice were topically inoculated and observed daily for keratitis severity. Corneal adaptation and pathogenicity were assessed ex vivo by maintaining infected porcine corneas for 3 days in an explantation culture system for histologic evaluation of hyphal penetration. RESULTS:All C. albicans strains had similar growth kinetics, and SC5314 and DAY185 demonstrated pH-induced filamentation. Fungal mutants had reduced hyphal formation at alkaline and neutral pH, but normal acidic assays ascertained that mutant strains did not have a generalized filamentation defect. SC5314 and DAY185 caused moderate to severe keratitis in mice, whereas fungal strains lacking constituents of the RIM101 pathway had significantly (P<0.05) attenuated severity in vivo. Three days after inoculation of porcine corneas, SC5314 and DAY185 produced hyphae that penetrated 28% and 25%, respectively, of the corneal thickness, and all five mutant strains showed significantly (P<0.05) less stromal penetration. CONCLUSIONS:The RIM101 signal transduction pathway plays an important role in the development of C. albicans keratitis. The fungal pathway intermediates Rim8p, Rim13p, Rim20p, and Rim101p and the downstream cell-wall protein Phr1p are pivotal in the process of corneal invasion by C. albicans.
    背景与目标: 目的:探讨真菌RIM101信号转导通路在白色念珠菌性角膜炎发病中的作用。
    方法:C。使用增殖和丝化测定法在体外评估了rim8,rim13,rim20,rim101和phr1基因的白色念珠菌野生型菌株SC5314,原养突变体对照DAY185和纯合真菌突变体。局部接种BALB / c和C57BL / 6J小鼠的角膜,每天观察角膜炎的严重程度。通过在外植体培养系统中将感染的猪角膜保持3天以进行菌丝穿透的组织学评估,离体评估了角膜的适应性和致病性。
    结果:所有白色念珠菌菌株均具有相似的生长动力学,SC5314和DAY185表现出pH诱导的丝化。真菌突变体在碱性和中性pH下具有减少的菌丝形成,但正常的酸性测定确定突变体菌株没有普遍的丝状化缺陷。 SC5314和DAY185在小鼠中引起中度至重度角膜炎,而缺少RIM101途径成分的真菌菌株在体内的严重程度明显降低(P <0.05)。猪角膜接种三天后,SC5314和DAY185产生的菌丝分别穿透了角膜厚度的28%和25%,并且所有五个突变菌株均显示出显着(P <0.05)的基质穿透。
    结论:RIM101信号转导通路在白色念珠菌性角膜炎的发生中起重要作用。真菌途径中间体Rim8p,Rim13p,Rim20p和Rim101p以及下游细胞壁蛋白Phr1p在白色念珠菌入侵角膜的过程中至关重要。
  • 【通过外部pH,ESCRT机制和酿酒酵母Rim101途径控制Bro1-domain蛋白Rim20的定位。】 复制标题 收藏 收藏
    DOI:10.1091/mbc.e05-10-0949 复制DOI
    作者列表:Boysen JH,Mitchell AP
    BACKGROUND & AIMS: :Bro1-domain proteins such as yeast Bro1 and mammalian AIP1/Alix are well-established participants in endosome metabolism. The Bro1-domain interacts with endosomal surface protein Snf7/Vps32 in yeast, a subunit of the ESCRT complex. Yeast Bro1-domain protein Rim20 has no role in endosome function, but is required for alkaline pH-stimulated cleavage of transcription factor Rim101. Rim20-GFP is cytoplasmic under acidic conditions but concentrated in punctate foci under alkaline conditions. Bro1-GFP also accumulates in foci, but they are more numerous under acidic than alkaline conditions. Colocalization experiments indicate that some Rim20-GFP foci correspond to Bro1-RFP foci, whereas others do not. Rim8, Rim9, Rim21, Dfg16, Snf7, Vps20, Vps23, and Vps25, which are required for Rim101 cleavage, are required for appearance of Rim20-GFP foci. ESCRT complexes accumulate on endosome-derived compartments in cells that lack the AAA-ATPase Vps4. We find that Rim20-GFP foci accumulate in a vps4 mutant background independently of external pH, Rim101 pathway-specific genes, and most ESCRT subunit genes except for SNF7. Rim20-GFP foci seem to represent endosomes, because they colocalize with Snf7-RFP and because they correspond to a perivacuolar compartment in the vps4 strain. We propose that alkaline growth conditions alter the endosomal surface to favor Rim20-Snf7 interaction and Rim101 cleavage. Our findings raise the possibility that Bro1-domain proteins may be differentially regulated in the same cell, thereby coupling endosome metabolism to signaling.
    背景与目标: :Bro1结构域蛋白,例如酵母Bro1和哺乳动物AIP1 / Alix,是内体代谢中公认的参与者。 Bro1结构域与酵母中的内体表面蛋白Snf7 / Vps32相互作用,后者是ESCRT复合物的亚基。酵母Bro1域蛋白Rim20在内体功能中没有作用,但是是碱性pH刺激的转录因子Rim101的裂解所必需的。 Rim20-GFP在酸性条件下为细胞质,但在碱性条件下集中在点状灶中。 Bro1-GFP也积累在病灶中,但是在酸性条件下比碱性条件下它们更多。共定位实验表明,一些Rim20-GFP灶对应于Bro1-RFP灶,而其他则不。 Rim101切割所需的Rim8,Rim9,Rim21,Dfg16,Snf7,Vps20,Vps23和Vps25是Rim20-GFP焦点的出现所必需的。 ESCRT复合物在缺乏AAA-ATPase Vps4的细胞中积累在内体来源的区室中。我们发现Rim20-GFP病灶积累在vps4突变体背景中,独立于外部pH,Rim101途径特异性基因和除SNF7以外的大多数ESCRT亚基基因。 Rim20-GFP灶似乎代表了内体,因为它们与Snf7-RFP共定位,并且因为它们对应于vps4菌株中的周壁室。我们建议碱性生长条件改变内体表面,以利于Rim20 Snf7相互作用和Rim101裂解。我们的发现提高了Bro1域蛋白在同一细胞中可能受到差异调节的可能性,从而将内体代谢耦合到信号传导上。
  • 【ESCRT-III蛋白Snf7通过Rim101途径介导SUC2基因的高水平表达。】 复制标题 收藏 收藏
    DOI:10.1128/EC.00194-08 复制DOI
    作者列表:Weiss P,Huppert S,Kölling R
    BACKGROUND & AIMS: :The yeast (Saccharomyces cerevisiae) Snf7 family consists of six highly charged, coiled-coil-forming proteins involved in multivesicular body (MVB) formation. Although all proteins perform a common function at late endosomes, individual mutants also show distinct phenotypes. This suggests that Snf7 homologues have additional functions separate from their role in MVB formation. In this report, we explored the molecular basis for the sucrose-nonfermenting phenotype of snf7 mutants. Our Northern blotting experiments provide evidence that Snf7 is involved in the regulation of SUC2 transcription. The Snf7-dependent regulation of SUC2 transcription does not appear to involve the transcription factor Mig1, since Mig1 phosphorylation after glucose derepression was not affected in a Deltasnf7 mutant. Instead, we show that Snf7 influences SUC2 expression by regulating the level of the transcription factor Nrg1. Snf7 exerts its effects on Nrg1 levels through activation of the transcription factor Rim101, which is part of the yeast alkaline response pathway ("Rim101 pathway"). This is supported by the findings that deletion of RIM101 or overexpression of NRG1 from the ADH1 promoter leads to the same SUC2 expression level as deletion of SNF7. In addition, deletion of other components of the Rim101 pathway, like RIM13 and RIM20, led to the same growth phenotype on raffinose media as deletion of SNF7. Furthermore, Snf7 turned out to be dispensable for SUC2 expression in an NRG1 deletion background. Thus, the effects of Snf7 on SUC2 expression can be completely accounted for by its effect on Nrg1 levels.
    背景与目标: :酵母(Saccharomyces cerevisiae)Snf7家族由六种高度带电荷的卷曲螺旋形成蛋白组成,这些蛋白参与多囊泡体(MVB)的形成。尽管所有蛋白质都在晚期内体中发挥共同的功能,但单个突变体也显示出不同的表型。这表明Snf7同源物除了在MVB形成中的作用外,还具有其他功能。在本报告中,我们探讨了snf7突变体蔗糖非发酵表型的分子基础。我们的RNA印迹实验提供了Snf7参与SUC2转录调控的证据。 SUC2转录的Snf7依赖性调节似乎不涉及转录因子Mig1,因为在Deltasnf7突变体中葡萄糖抑制后的Mig1磷酸化不受影响。相反,我们显示Snf7通过调节转录因子Nrg1的水平影响SUC2表达。 Snf7通过激活转录因子Rim101来发挥其对Nrg1水平的影响,Rim101是酵母碱性反应途径(“ Rim101途径”)的一部分。这由以下发现支持:RIM101的缺失或ADH1启动子中NRG1的过表达导致与SNF7缺失相同的SUC2表达水平。此外,Rim101途径的其他成分(如RIM13和RIM20)的缺失导致棉子糖培养基上的生长表型与SNF7的缺失相同。此外,事实证明,Snf7对于NRG1缺失背景中的SUC2表达而言是可有可无的。因此,Snf7对SUC2表达的影响可以完全通过其对Nrg1水平的影响来解释。
  • 【白色念珠菌ESCRT途径对发病机制具有Rim101依赖性和非依赖性作用。】 复制标题 收藏 收藏
    DOI:10.1128/EC.00056-10 复制DOI
    作者列表:Wolf JM,Johnson DJ,Chmielewski D,Davis DA
    BACKGROUND & AIMS: :Candida albicans is an opportunistic pathogen that colonizes diverse mucosal niches with distinct environmental characteristics. To adapt to these different sites, C. albicans must activate and attenuate a variety of signal transduction pathways. A mechanism of signal attenuation is through receptor endocytosis and subsequent vacuolar degradation, which requires the endosomal sorting complex required for transport (ESCRT) pathway. This pathway comprises several polyprotein complexes (ESCRT-0, -I, -II, -III, and -DS) that are sequentially recruited to the endosomal membrane. The ESCRT pathway also activates the Rim101 transcription factor, which governs expression of genes required for virulence. Here, we tested the hypothesis that the ESCRT pathway plays a Rim101-independent role(s) in pathogenesis. We generated deletion mutants in each ESCRT complex and determined that ESCRT-I, -II, and -III are required for Rim101 activation but that ESCRT-0 and ESCRT-DS are not. We found that the ESCRT-0 member Vps27 and ESCRT-DS components are required to promote epithelial cell damage and, using a murine model of oral candidiasis, found that the vps27Delta/Delta mutant had a decreased fungal burden compared to that of the wild type. We found that a high-dose inoculum can compensate for fungal burden defects but that mice colonized with the vps27Delta/Delta strain exhibit less morbidity than do mice infected with the wild-type strain. These results demonstrate that the ESCRT pathway has Rim101-independent functions for C. albicans virulence.
    背景与目标: :白色念珠菌是一种机会病原体,它定居在具有独特环境特征的各种粘膜壁ni中。为了适应这些不同的位置,白色念珠菌必须激活并减弱各种信号转导途径。信号衰减的机制是通过受体内吞作用和随后的液泡降解,这需要转运所需的内体分选复合物(ESCRT)途径。该途径包含依次募集到内体膜的几种多蛋白复合物(ESCRT-0,-I,-II,-III和-DS)。 ESCRT途径还激活Rim101转录因子,该因子控制毒力所需基因的表达。在这里,我们测试了ESCRT途径在发病机制中起Rim101独立作用的假设。我们在每个ESCRT复合物中生成了缺失突变体,并确定ESCRT-1,-II和-III是激活Rim101所必需的,而ESCRT-0和ESCRT-DS不是必需的。我们发现ESCRT-0成员Vps27和ESCRT-DS成分是促进上皮细胞损伤所必需的,并且使用口腔念珠菌病的鼠模型,发现vps27Delta / Delta突变体与野生型相比具有降低的真菌负担。我们发现高剂量接种物可以补偿真菌负荷缺陷,但是定居于vps27Delta / Delta菌株的小鼠的发病率要低于感染野生型菌株的小鼠。这些结果表明,ESCRT途径对白色念珠菌的毒力具有Rim101独立的功能。
  • 【酵母解脂耶氏酵母中依赖Rim101的环境pH调节需要内吞机器的ESCRT-I组件。】 复制标题 收藏 收藏
    DOI:10.1099/mic.0.28196-0 复制DOI
    作者列表:Blanchin-Roland S,Costa GD,Gaillardin C
    BACKGROUND & AIMS: :Ambient pH signalling involves a cascade of conserved Rim or Pal products in ascomycetous yeasts or filamentous fungi, respectively. Insertional mutagenesis in the yeast Yarrowia lipolytica identified two components of the endosome-associated ESCRT-I complex involved in multivesicular body (MVB) vesicle formation, YlVps28p and YlVps23p. They were shown to be required at alkaline pH, like Rim factors, for transcriptional activation of alkaline-induced genes and repression of acid-induced genes. The constitutively active YlRIM101-1119 allele, which suppresses the pH-signalling defects of Ylrim mutations, also suppresses Ylvps defects in pH response, but not in endocytosis. The contribution of the ESCRT-III component Snf7p could not be assessed due to the essential nature of this component in Y. lipolytica. Unlike Rim factors, YlVps4p, a component of the MVB pathway acting downstream from ESCRT complexes, seems not to be required for the alkaline response. In Y. lipolytica, all vps mutations including those affecting YlVPS4, affected growth at acidic pH, a feature not exhibited by Ylrim mutations. These results suggest that Rim and Vps pathways cooperate in ambient pH signalling and that this relation is conserved across the full range of hemiascomycetous yeasts.
    背景与目标: :环境pH信号涉及分别在子囊酵母或丝状真菌中级联的保守的Rim或Pal产物。酵母解脂耶氏酵母中的插入诱变鉴定了与多囊体(MVB)囊泡形成有关的内体相关的ESCRT-1复合物的两个组分,Y1Vps28p和Y1Vps23p。已显示出它们需要像Rim因子一样在碱性pH值下对碱性诱导的基因进行转录激活并抑制酸性诱导的基因。抑制Ylrim突变的pH信号缺陷的组成型活性Y1RIM101-1119等位基因,也抑制pH响应中的Ylvps缺陷,但不抑制内吞作用。由于解脂耶氏酵母中该成分的本质,因此无法评估ESCRT-III成分Snf7p的贡献。与Rim因子不同,Y1Vps4p是在ESCRT复合物中下游起作用的MVB途径的一个组成部分,似乎对于碱性反应不是必需的。在解脂耶氏酵母中,所有vps突变(包括那些影响Y1VPS4的突变)都在酸性pH下影响了生长,这是Ylrim突变所没有表现出的特征。这些结果表明,Rim和Vps途径在环境pH信号转导中协同作用,并且这种关系在整个半糖酵母中都得到了保留。
  • 【转录因子Rim101的快速周转证实了酿酒酵母对环境压力的灵活适应机制。】 复制标题 收藏 收藏
    DOI:10.1111/gtc.12801 复制DOI
    作者列表:Obara K,Higuchi M,Ogura Y,Nishimura K,Kamura T
    BACKGROUND & AIMS: :Saccharomyces cerevisiae cells activate the Rim101 pathway to adapt to alkaline and salt stresses. On activation of this pathway, the transcription factor Rim101 undergoes proteolytic activation and regulates the expression of responsive genes. We found Rim101 to be a short-lived protein with a half-life of approximately 15 min. Its rapid turnover was supposedly mediated by the ubiquitin-proteasome system. Excess accumulation of the processed active Rim101 through its over-expression conferred tolerance to both alkaline and salt stresses in yeast cells; in contrast, it had detrimental effects under cadmium stress condition. Cadmium ion inhibited proteolytic activation of Rim101, implying reciprocal interaction between the Rim101 pathway and cadmium stress. Our results showed yeast cells to be equipped with two protective systems to prevent overaccumulation of the processed active Rim101; Rim101 processing is inhibited when Rim101 level is high, and turnover of processed Rim101 is accelerated when it is abundant. Collectively, the results confirmed the flexible aspect of stress response in yeast cell; the cells not only prevent excess activation of one stress-responsive pathway but also facilitate its attenuation to cope with other environmental stresses.
    背景与目标: :酿酒酵母细胞激活Rim101途径以适应碱性和盐胁迫。激活该途径后,转录因子Rim101进行蛋白水解激活并调节反应性基因的表达。我们发现Rim101是一种短暂的蛋白质,半衰期约为15分钟。据称它的快速周转是由泛素-蛋白酶体系统介导的。加工过的活性Rim101的过量表达导致的过量积累赋予了其对酵母细胞中碱和盐胁迫的耐受性;相反,它在镉胁迫条件下具有有害作用。镉离子抑制Rim101的蛋白水解激活,这暗示Rim101途径与镉胁迫之间的相互作用。我们的结果表明,酵母细胞配备了两个保护系统,以防止加工过的活性Rim101过度积聚。当Rim101的水平高时,Rim101的处理被禁止,而当Rim101的水平高时,则处理的Rim101的营业额被加速。总体而言,结果证实了酵母细胞中应激反应的灵活方面。这些细胞不仅阻止了一种应激反应途径的过度激活,而且还促进了其衰减以应对其他环境胁迫。
  • 【RIM101依赖性和非依赖性途径控制白色念珠菌的pH响应。】 复制标题 收藏 收藏
    DOI:10.1128/mcb.20.3.971-978.2000 复制DOI
    作者列表:Davis D,Wilson RB,Mitchell AP
    BACKGROUND & AIMS: :Growth and differentiation of Candida albicans over a broad pH range underlie its ability to infect an array of tissues in susceptible hosts. We identified C. albicans RIM101, RIM20, and RIM8 based on their homology to components of the one known fungal pH response pathway. PCR product-disruption mutations in each gene cause defects in three responses to alkaline pH: filamentation, induction of PRA1 and PHR1, and repression of PHR2. We find that RIM101 itself is an alkaline-induced gene that also depends on Rim20p and Rim8p for induction. Two observations indicate that a novel pH response pathway also exists. First, PHR2 becomes an alkaline-induced gene in the absence of Rim101p, Rim20p, or Rim8p. Second, we created strains in which Rim101p activity is independent of Rim20p and Rim8p; in these strains, filamentation remains pH dependent. Thus, pH governs gene expression and cellular differentiation in C. albicans through both RIM101-dependent and RIM101-independent pathways.
    背景与目标: :白色念珠菌在广泛的pH范围内的生长和分化是其感染易感宿主的一系列组织的能力的基础。我们基于白色念珠菌RIM101,RIM20和RIM8与一种已知真菌pH响应途径的组成部分的同源性进行了鉴定。每个基因中的PCR产物破坏突变都会导致对碱性pH值的三种反应出现缺陷:丝状化,PRA1和PHR1的诱导以及PHR2的抑制。我们发现RIM101本身是碱性诱导的基因,其诱导也依赖于Rim20p和Rim8p。两项观察结果表明,还存在一种新型的pH响应途径。首先,在缺少Rim101p,Rim20p或Rim8p的情况下,PHR2成为碱性诱导的基因。其次,我们创建了其中Rim101p活性独立于Rim20p和Rim8p的菌株。在这些菌株中,丝状化仍然依赖于pH。因此,pH通过RIM101依赖性和RIM101依赖性途径控制白色念珠菌的基因表达和细胞分化。
  • 【RIM101(PRR2)的主要活性等位基因绕过白色假丝酵母丝的pH限制。】 复制标题 收藏 收藏
    DOI:10.1128/mcb.20.13.4635-4647.2000 复制DOI
    作者列表:El Barkani A,Kurzai O,Fonzi WA,Ramon A,Porta A,Frosch M,Mühlschlegel FA
    BACKGROUND & AIMS: :Morphological development of the fungal pathogen Candida albicans is profoundly affected by ambient pH. Acidic pH restricts growth to the yeast form, whereas neutral pH permits development of the filamentous form. Superimposed on the pH restriction is a temperature requirement of approximately 37 degrees C for filamentation. The role of pH in development was investigated by selecting revertants of phr2Delta mutants that had gained the ability to grow at acid pH. The extragenic suppressors in two independent revertants were identified as nonsense mutations in the pH response regulator RIM101 (PRR2) that resulted in a carboxy-terminal truncation of the open reading frame. These dominant active alleles conferred the ability to filament at acidic pH, to express PHR1, an alkaline-expressed gene, at acidic pH, and to repress the acid-expressed gene PHR2. It was also observed that both the wild-type and mutant alleles could act as multicopy suppressors of the temperature restriction on filamentation, allowing extensive filamentation at 29 degrees C. The ability of the activated alleles to promote filamentation was dependent upon the developmental regulator EFG1. The results suggest that RIM101 is responsible for the pH dependence of hyphal development.
    背景与目标: :真菌病原体白色念珠菌的形态发育受到环境pH的深刻影响。酸性pH限制了酵母形式的生长,而中性pH允许形成丝状形式。在pH限制上叠加了长丝所需的温度约为37摄氏度。通过选择具有在酸性pH条件下生长能力的phr2Delta突变体的回复株,研究了pH在发育中的作用。在两个独立回复子中的外源抑制剂被鉴定为pH响应调节剂RIM101(PRR2)中的无意义突变,导致开放阅读框的羧基末端被截断。这些占优势的活性等位基因赋予了在酸性pH下发丝,表达PHR1(在碱性pH下表达碱性表达的基因)和抑制酸性表达基因PHR2的能力。还观察到,野生型和突变型等位基因均可以充当丝状体温度限制的多拷贝抑制剂,从而允许在29摄氏度下广泛地丝状化。活化的等位基因促进丝状体形成的能力取决于发育调节剂EFG1。结果表明RIM101负责菌丝发育的pH依赖性。
  • 【内吞性成分VPS28和VPS32的缺失会通过白色念珠菌中RIM101依赖性和RIM101依赖性途径影响碱性pH和毒力下的生长。】 复制标题 收藏 收藏
    DOI:10.1128/IAI.73.12.7977-7987.2005 复制DOI
    作者列表:Cornet M,Bidard F,Schwarz P,Da Costa G,Blanchin-Roland S,Dromer F,Gaillardin C
    BACKGROUND & AIMS: :Ambient pH signaling involves a cascade of conserved Rim or Pal products in ascomycetous yeasts or filamentous fungi, respectively. Recent evidences in the fungi Aspergillus nidulans, Saccharomyces cerevisiae, Yarrowia lipolytica, and Candida albicans suggested that components of endosomal sorting complexes required for transport (ESCRT) involved in endocytic trafficking were needed for signal transduction along the Rim pathway. In this study, we confirm these findings with C. albicans and show that Vps28p (ESCRT-I) and Vps32p/Snf7p (ESCRT-III) are required for the transcriptional regulation of known targets of the Rim pathway, such as the PHR1 and PHR2 genes encoding cell surface proteins, which are expressed at alkaline and acidic pH, respectively. We additionally show that deletion of these two VPS genes, particularly VPS32, has a more drastic effect than a RIM101 deletion on growth at alkaline pH and that this effect is only partially suppressed by expression of a constitutively active form of Rim101p. Finally, in an in vivo mouse model, both vps null mutants were significantly less virulent than a rim101 mutant, suggesting that VPS28 and VPS32 gene products affect virulence both through Rim-dependent and Rim-independent pathways.
    背景与目标: :环境pH信号涉及分别在子囊酵母或丝状真菌中级联的保守的Rim或Pal产物。在真菌曲霉,酿酒酵母,解脂耶氏酵母和白色念珠菌中的最新证据表明,参与内吞运输的运输所需的内体分选复合物(ESCRT)的成分需要沿Rim途径进行信号转导。在这项研究中,我们用白色念珠菌证实了这些发现,并显示了Rps途径的已知靶标(例如PHR1和PHR2)的转录调控需要Vps28p(ESCRT-I)和Vps32p / Snf7p(ESCRT-III)基因编码细胞表面蛋白,分别在碱性和酸性pH下表达。我们还显示,在碱性pH值下,这两个VPS基因(尤其是VPS32)的缺失比RIM101缺失对生长的影响更大,并且仅通过Rim101p的组成型活性形式的表达来部分抑制这种作用。最后,在体内小鼠模型中,两个vps null突变体的毒性都比rim101突变体低得多,这表明VPS28和VPS32基因产物通过Rim依赖性和Rim依赖性途径影响毒力。
  • 【新型隐球菌Rim101和蛋白激酶A的相互作用调节胶囊。】 复制标题 收藏 收藏
    DOI:10.1371/journal.ppat.1000776 复制DOI
    作者列表:O'Meara TR,Norton D,Price MS,Hay C,Clements MF,Nichols CB,Alspaugh JA
    BACKGROUND & AIMS: :Good's syndrome (GS) is a rare acquired combined T- and B-cell immunodeficiency accompanying thymoma. This report concerns a case of a 57-year-old man with GS manifesting intractable opportunistic infections and hyperkeratotic lichen planus. He had a past history of extended thymectomy for removal of thymoma. He consulted us about scaly and exudative intractable erythematous plaque on his right forearm. The histology was compatible with phlegmon coexisting with lichen planus. Laboratory examination results indicated hypogammaglobulinemia accompanied by complete absence of B cells, which is consistent with GS. Combined treatment with immunoglobulin replacement and administration of antibiotics and antifungal drugs was effective for the phlegmon and overlying fungal infection. The patient also presented with hyperkeratotic lichen planus on both knees and the right elbow, suggesting that intractable opportunistic infection and lichen planus may be associated with GS.
    背景与目标: :Good's综合征(GS)是伴有胸腺瘤的一种罕见的获得性T细胞和B细胞免疫缺陷综合症。该报告涉及一例GS的57岁男子,该男子表现出顽固的机会性感染和角化过度的扁平苔藓。他有去除胸腺瘤的扩大胸腺切除术的历史。他向我们咨询了右前臂上的鳞状和渗出性难治性红斑。组织学与扁平苔藓并存的痰菌相容。实验室检查结果表明低血球蛋白血症伴有B细胞的完全缺失,这与GS一致。结合免疫球蛋白替代疗法和抗生素及抗真菌药物的联合治疗对痰菌和上层真菌感染均有效。该患者在膝盖和右肘上均出现角化过度的扁平苔藓,提示难治性机会性感染和扁平苔藓可能与GS有关。
  • 【RIM101途径有助于酵母细胞壁的组装,在缺乏促分裂原活化蛋白激酶Slt2p的情况下,其功能变得至关重要。】 复制标题 收藏 收藏
    DOI:10.1128/EC.5.3.507-517.2006 复制DOI
    作者列表:["Castrejon F","Gomez A","Sanz M","Duran A","Roncero C"]
    BACKGROUND & AIMS:
    背景与目标:
  • 【RIM101途径在酿酒酵母的适应性反应中具有作用,并对丙酸和其他弱酸具有抗性。】 复制标题 收藏 收藏
    DOI:10.1111/j.1567-1364.2008.00473.x 复制DOI
    作者列表:Mira NP,Lourenço AB,Fernandes AR,Becker JD,Sá-Correia I
    BACKGROUND & AIMS:
    背景与目标:
  • 【Rim101途径参与脂质不对称性改变引起的Rsb1表达。】 复制标题 收藏 收藏
    DOI:10.1091/mbc.e07-08-0806 复制DOI
    作者列表:Ikeda M,Kihara A,Denpoh A,Igarashi Y
    BACKGROUND & AIMS:
    背景与目标:
  • 【新型隐球菌Rim101转录因子直接调节适应宿主所需的基因。】 复制标题 收藏 收藏
    DOI:10.1128/MCB.01359-13 复制DOI
    作者列表:O'Meara TR,Xu W,Selvig KM,O'Meara MJ,Mitchell AP,Alspaugh JA
    BACKGROUND & AIMS:
    背景与目标:

+1
+2
100研值 100研值 ¥99课程
检索文献一次
下载文献一次

去下载>

成功解锁2个技能,为你点赞

《SCI写作十大必备语法》
解决你的SCI语法难题!

技能熟练度+1

视频课《玩转文献检索》
让你成为检索达人!

恭喜完成新手挑战

手机微信扫一扫,添加好友领取

免费领《Endnote文献管理工具+教程》

微信扫码, 免费领取

手机登录

获取验证码
登录