Eukaryotic Cell最新文献

Depletion of UBC9 Causes Nuclear Defects during the Vegetative and Sexual Life Cycles in Tetrahymena thermophila. 在嗜热四膜虫的营养和有性生命周期中，UBC9的缺失导致核缺陷。

Eukaryotic Cell Pub Date : 2015-12-01 Epub Date: 2015-10-09 DOI: 10.1128/EC.00115-15

Qianyi Yang, Amjad M Nasir, Robert S Coyne, James D Forney

{"title":"Depletion of UBC9 Causes Nuclear Defects during the Vegetative and Sexual Life Cycles in Tetrahymena thermophila.","authors":"Qianyi Yang, Amjad M Nasir, Robert S Coyne, James D Forney","doi":"10.1128/EC.00115-15","DOIUrl":"https://doi.org/10.1128/EC.00115-15","url":null,"abstract":"Ubc9p is the sole E2-conjugating enzyme for SUMOylation, and its proper function is required for regulating key nuclear events such as transcription, DNA repair, and mitosis. In Tetrahymena thermophila, the genome is separated into a diploid germ line micronucleus (MIC) that divides by mitosis and a polyploid somatic macronucleus (MAC) that divides amitotically. This unusual nuclear organization provides novel opportunities for the study of SUMOylation and Ubc9p function. We identified the UBC9 gene and demonstrated that its complete deletion from both MIC and MAC genomes is lethal. Rescue of the lethal phenotype with a GFP-UBC9 fusion gene driven by a metallothionein promoter generated a cell line with CdCl2-dependent expression of green fluorescent protein (GFP)-Ubc9p. Depletion of Ubc9p in vegetative cells resulted in the loss of MICs, but MACs continued to divide. In contrast, expression of catalytically inactive Ubc9p resulted in the accumulation of multiple MICs. Critical roles for Ubc9p were also identified during the sexual life cycle of Tetrahymena. Cell lines that were depleted for Ubc9p did not form mating pairs and therefore could not complete any of the subsequent stages of conjugation, including meiosis and macronuclear development. Mating between cells expressing catalytically inactive Ubc9p resulted in arrest during macronuclear development, consistent with our observation that Ubc9p accumulates in the developing macronucleus. ","PeriodicalId":11891,"journal":{"name":"Eukaryotic Cell","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2015-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1128/EC.00115-15","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"34077162","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 3

N-Terminal Presequence-Independent Import of Phosphofructokinase into Hydrogenosomes of Trichomonas vaginalis. 阴道毛滴虫氢酶体中磷酸果糖激酶n端不依赖于序列的输入。

Eukaryotic Cell Pub Date : 2015-12-01 Epub Date: 2015-10-16 DOI: 10.1128/EC.00104-15

Petr Rada, Abhijith Radhakrishna Makki, Verena Zimorski, Sriram Garg, Vladimír Hampl, Ivan Hrdý, Sven B Gould, Jan Tachezy

{"title":"N-Terminal Presequence-Independent Import of Phosphofructokinase into Hydrogenosomes of Trichomonas vaginalis.","authors":"Petr Rada, Abhijith Radhakrishna Makki, Verena Zimorski, Sriram Garg, Vladimír Hampl, Ivan Hrdý, Sven B Gould, Jan Tachezy","doi":"10.1128/EC.00104-15","DOIUrl":"https://doi.org/10.1128/EC.00104-15","url":null,"abstract":"Mitochondrial evolution entailed the origin of protein import machinery that allows nuclear-encoded proteins to be targeted to the organelle, as well as the origin of cleavable N-terminal targeting sequences (NTS) that allow efficient sorting and import of matrix proteins. In hydrogenosomes and mitosomes, reduced forms of mitochondria with reduced proteomes, NTS-independent targeting of matrix proteins is known. Here, we studied the cellular localization of two glycolytic enzymes in the anaerobic pathogen Trichomonas vaginalis: PPi-dependent phosphofructokinase (TvPPi-PFK), which is the main glycolytic PFK activity of the protist, and ATP-dependent PFK (TvATP-PFK), the function of which is less clear. TvPPi-PFK was detected predominantly in the cytosol, as expected, while all four TvATP-PFK paralogues were imported into T. vaginalis hydrogenosomes, although none of them possesses an NTS. The heterologous expression of TvATP-PFK in Saccharomyces cerevisiae revealed an intrinsic capability of the protein to be recognized and imported into yeast mitochondria, whereas yeast ATP-PFK resides in the cytosol. TvATP-PFK consists of only a catalytic domain, similarly to \"short\" bacterial enzymes, while ScATP-PFK includes an N-terminal extension, a catalytic domain, and a C-terminal regulatory domain. Expression of the catalytic domain of ScATP-PFK and short Escherichia coli ATP-PFK in T. vaginalis resulted in their partial delivery to hydrogenosomes. These results indicate that TvATP-PFK and the homologous ATP-PFKs possess internal structural targeting information that is recognized by the hydrogenosomal import machinery. From an evolutionary perspective, the predisposition of ancient ATP-PFK to be recognized and imported into hydrogenosomes might be a relict from the early phases of organelle evolution. ","PeriodicalId":11891,"journal":{"name":"Eukaryotic Cell","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2015-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1128/EC.00104-15","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"34094452","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 20

Virulence-Associated Enzymes of Cryptococcus neoformans. 新型隐球菌毒力相关酶研究。

Eukaryotic Cell Pub Date : 2015-12-01 Epub Date: 2015-10-09 DOI: 10.1128/EC.00103-15

Fausto Almeida, Julie M Wolf, Arturo Casadevall

引用次数: 82

Correction for Liang et al., A Novel Function for Hog1 Stress-Activated Protein Kinase in Controlling White-Opaque Switching and Mating in Candida albicans 更正Liang等人，Hog1应激激活蛋白激酶在控制白色念珠菌白色不透明开关和交配中的新功能

Eukaryotic Cell Pub Date : 2015-12-01 DOI: 10.1128/EC.00005-16

Shen-Huan Liang, J. Cheng, Fu-Sheng Deng, Pei-An Tsai, Ching-Hsuan Lin

引用次数: 0

The ABCs of Candida albicans Multidrug Transporter Cdr1. 白色念珠菌多药转运蛋白Cdr1的abc。

Eukaryotic Cell Pub Date : 2015-12-01 Epub Date: 2015-09-25 DOI: 10.1128/EC.00137-15

Rajendra Prasad, Atanu Banerjee, Nitesh Kumar Khandelwal, Sanjiveeni Dhamgaye

{"title":"The ABCs of Candida albicans Multidrug Transporter Cdr1.","authors":"Rajendra Prasad, Atanu Banerjee, Nitesh Kumar Khandelwal, Sanjiveeni Dhamgaye","doi":"10.1128/EC.00137-15","DOIUrl":"https://doi.org/10.1128/EC.00137-15","url":null,"abstract":"In the light of multidrug resistance (MDR) among pathogenic microbes and cancer cells, membrane transporters have gained profound clinical significance. Chemotherapeutic failure, by far, has been attributed mainly to the robust and diverse array of these proteins, which are omnipresent in every stratum of the living world. Candida albicans, one of the major fungal pathogens affecting immunocompromised patients, also develops MDR during the course of chemotherapy. The pivotal membrane transporters that C. albicans has exploited as one of the strategies to develop MDR belongs to either the ATP binding cassette (ABC) or the major facilitator superfamily (MFS) class of proteins. The ABC transporter Candida drug resistance 1 protein (Cdr1p) is a major player among these transporters that enables the pathogen to outplay the battery of antifungals encountered by it. The promiscuous Cdr1 protein fulfills the quintessential need of a model to study molecular mechanisms of multidrug transporter regulation and structure-function analyses of asymmetric ABC transporters. In this review, we cover the highlights of two decades of research on Cdr1p that has provided a platform to study its structure-function relationships and regulatory circuitry for a better understanding of MDR not only in yeast but also in other organisms. ","PeriodicalId":11891,"journal":{"name":"Eukaryotic Cell","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2015-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1128/EC.00137-15","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"34207143","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 78

Erratum for Yamamoto et al., Novel 44-Kilodalton Subunit of Axonemal Dynein Conserved from Chlamydomonas to Mammals. 对Yamamoto等人的勘误，从衣藻到哺乳动物的轴索动力蛋白的新44千道尔顿亚基的保守。

Eukaryotic Cell Pub Date : 2015-12-01 Epub Date: 2017-03-15 DOI: 10.1128/EC.00001-17

Ryosuke Yamamoto, Haru-Aki Yanagisawa, Toshiki Yagi, Ritsu Kamiya

引用次数: 0

Adaptations of the Secretome of Candida albicans in Response to Host-Related Environmental Conditions. 白色念珠菌分泌组对宿主相关环境条件的适应。

Eukaryotic Cell Pub Date : 2015-12-01 Epub Date: 2015-10-09 DOI: 10.1128/EC.00142-15

Frans M Klis, Stanley Brul

{"title":"Adaptations of the Secretome of Candida albicans in Response to Host-Related Environmental Conditions.","authors":"Frans M Klis, Stanley Brul","doi":"10.1128/EC.00142-15","DOIUrl":"https://doi.org/10.1128/EC.00142-15","url":null,"abstract":"The wall proteome and the secretome of the fungal pathogen Candida albicans help it to thrive in multiple niches of the human body. Mass spectrometry has allowed researchers to study the dynamics of both subproteomes. Here, we discuss some major responses of the secretome to host-related environmental conditions. Three β-1,3-glucan-modifying enzymes, Mp65, Sun41, and Tos1, are consistently found in large amounts in culture supernatants, suggesting that they are needed for construction and expansion of the cell wall β-1,3-glucan layer and thus correlate with growth and might serve as diagnostic biomarkers. The genes ENG1, CHT3, and SCW11, which encode an endoglucanase, the major chitinase, and a β-1,3-glucan-modifying enzyme, respectively, are periodically expressed and peak in M/G1. The corresponding protein abundances in the medium correlate with the degree of cell separation during single-yeast-cell, pseudohyphal, and hyphal growth. We also discuss the observation that cells treated with fluconazole, or other agents causing cell surface stress, form pseudohyphal aggregates. Fluconazole-treated cells secrete abundant amounts of the transglucosylase Phr1, which is involved in the accumulation of β-1,3-glucan in biofilms, raising the question whether this is a general response to cell surface stress. Other abundant secretome proteins also contribute to biofilm formation, emphasizing the important role of secretome proteins in this mode of growth. Finally, we discuss the relevance of these observations to therapeutic intervention. Together, these data illustrate that C. albicans actively adapts its secretome to environmental conditions, thus promoting its survival in widely divergent niches of the human body. ","PeriodicalId":11891,"journal":{"name":"Eukaryotic Cell","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2015-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1128/EC.00142-15","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"34077159","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 17

Retraction for Chavez-Dozal et al. Functional Analysis of the Exocyst Subunit Sec15 in Candida albicans. 撤销 Chavez-Dozal 等人的文章：白色念珠菌外囊亚基 Sec15 的功能分析。

Eukaryotic Cell Pub Date : 2015-12-01 DOI: 10.1128/EC.00002-16

Alba A Chavez-Dozal, Stella M Bernardo, Hallie S Rane, Samuel A Lee

引用次数: 0

Yeast Integral Membrane Proteins Apq12, Brl1, and Brr6 Form a Complex Important for Regulation of Membrane Homeostasis and Nuclear Pore Complex Biogenesis. 酵母整体膜蛋白Apq12, Brl1和Brr6形成一个对膜稳态调节和核孔复合体生物发生重要的复合体。

Eukaryotic Cell Pub Date : 2015-12-01 Epub Date: 2015-10-02 DOI: 10.1128/EC.00101-15

Museer A Lone, Aaron E Atkinson, Christine A Hodge, Stéphanie Cottier, Fernando Martínez-Montañés, Shelley Maithel, Laurent Mène-Saffrané, Charles N Cole, Roger Schneiter

{"title":"Yeast Integral Membrane Proteins Apq12, Brl1, and Brr6 Form a Complex Important for Regulation of Membrane Homeostasis and Nuclear Pore Complex Biogenesis.","authors":"Museer A Lone, Aaron E Atkinson, Christine A Hodge, Stéphanie Cottier, Fernando Martínez-Montañés, Shelley Maithel, Laurent Mène-Saffrané, Charles N Cole, Roger Schneiter","doi":"10.1128/EC.00101-15","DOIUrl":"https://doi.org/10.1128/EC.00101-15","url":null,"abstract":"Proper functioning of intracellular membranes is critical for many cellular processes. A key feature of membranes is their ability to adapt to changes in environmental conditions by adjusting their composition so as to maintain constant biophysical properties, including fluidity and flexibility. Similar changes in the biophysical properties of membranes likely occur when intracellular processes, such as vesicle formation and fusion, require dramatic changes in membrane curvature. Similar modifications must also be made when nuclear pore complexes (NPCs) are constructed within the existing nuclear membrane, as occurs during interphase in all eukaryotes. Here we report on the role of the essential nuclear envelope/endoplasmic reticulum (NE/ER) protein Brl1 in regulating the membrane composition of the NE/ER. We show that Brl1 and two other proteins characterized previously-Brr6, which is closely related to Brl1, and Apq12-function together and are required for lipid homeostasis. All three transmembrane proteins are localized to the NE and can be coprecipitated. As has been shown for mutations affecting Brr6 and Apq12, mutations in Brl1 lead to defects in lipid metabolism, increased sensitivity to drugs that inhibit enzymes involved in lipid synthesis, and strong genetic interactions with mutations affecting lipid metabolism. Mutations affecting Brl1 or Brr6 or the absence of Apq12 leads to hyperfluid membranes, because mutant cells are hypersensitive to agents that increase membrane fluidity. We suggest that the defects in nuclear pore complex biogenesis and mRNA export seen in these mutants are consequences of defects in maintaining the biophysical properties of the NE. ","PeriodicalId":11891,"journal":{"name":"Eukaryotic Cell","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2015-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1128/EC.00101-15","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"34056646","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 34

Retraction for Chavez-Dozal et al., The Candida albicans Exocyst Subunit Sec6 Contributes to Cell Wall Integrity and Is a Determinant of Hyphal Branching. 撤回 Chavez-Dozal 等人的文章，《白色念珠菌外囊亚基 Sec6 有助于细胞壁的完整性并决定着菌体的分枝》。

Eukaryotic Cell Pub Date : 2015-12-01 DOI: 10.1128/EC.00001-16

Alba A Chavez-Dozal, Stella M Bernardo, Hallie S Rane, Gloria Herrera, Vibhati Kulkarny, Jeanette Wagener, Iain Cunningham, Alexandra C Brand, Neil A R Gow, Samuel A Lee

引用次数: 0