1
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Prokisch S, Büttner S. Partitioning into ER membrane microdomains impacts autophagic protein turnover during cellular aging. Sci Rep 2024; 14:13653. [PMID: 38871812 DOI: 10.1038/s41598-024-64493-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2023] [Accepted: 06/09/2024] [Indexed: 06/15/2024] Open
Abstract
Eukaryotic membranes are compartmentalized into distinct micro- and nanodomains that rearrange dynamically in response to external and internal cues. This lateral heterogeneity of the lipid bilayer and associated clustering of distinct membrane proteins contribute to the spatial organization of numerous cellular processes. Here, we show that membrane microdomains within the endoplasmic reticulum (ER) of yeast cells are reorganized during metabolic reprogramming and aging. Using biosensors with varying transmembrane domain length to map lipid bilayer thickness, we demonstrate that in young cells, microdomains of increased thickness mainly exist within the nuclear ER, while progressing cellular age drives the formation of numerous microdomains specifically in the cortical ER. Partitioning of biosensors with long transmembrane domains into these microdomains increased protein stability and prevented autophagic removal. In contrast, reporters with short transmembrane domains progressively accumulated at the membrane contact site between the nuclear ER and the vacuole, the so-called nucleus-vacuole junction (NVJ), and were subjected to turnover via selective microautophagy occurring specifically at these sites. Reporters with long transmembrane domains were excluded from the NVJ. Our data reveal age-dependent rearrangement of the lateral organization of the ER and establish transmembrane domain length as a determinant of membrane contact site localization and autophagic degradation.
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Affiliation(s)
- Simon Prokisch
- Department of Molecular Biosciences, The Wenner-Gren Institute, Stockholm University, 10691, Stockholm, Sweden
| | - Sabrina Büttner
- Department of Molecular Biosciences, The Wenner-Gren Institute, Stockholm University, 10691, Stockholm, Sweden.
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2
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Moretti-Horten DN, Peselj C, Taskin AA, Myketin L, Schulte U, Einsle O, Drepper F, Luzarowski M, Vögtle FN. Synchronized assembly of the oxidative phosphorylation system controls mitochondrial respiration in yeast. Dev Cell 2024; 59:1043-1057.e8. [PMID: 38508182 DOI: 10.1016/j.devcel.2024.02.011] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2023] [Revised: 01/19/2024] [Accepted: 02/28/2024] [Indexed: 03/22/2024]
Abstract
Control of protein stoichiometry is essential for cell function. Mitochondrial oxidative phosphorylation (OXPHOS) presents a complex stoichiometric challenge as the ratio of the electron transport chain (ETC) and ATP synthase must be tightly controlled, and assembly requires coordinated integration of proteins encoded in the nuclear and mitochondrial genome. How correct OXPHOS stoichiometry is achieved is unknown. We identify the Mitochondrial Regulatory hub for respiratory Assembly (MiRA) platform, which synchronizes ETC and ATP synthase biogenesis in yeast. Molecularly, this is achieved by a stop-and-go mechanism: the uncharacterized protein Mra1 stalls complex IV assembly. Two "Go" signals are required for assembly progression: binding of the complex IV assembly factor Rcf2 and Mra1 interaction with an Atp9-translating mitoribosome induce Mra1 degradation, allowing synchronized maturation of complex IV and the ATP synthase. Failure of the stop-and-go mechanism results in cell death. MiRA controls OXPHOS assembly, ensuring correct stoichiometry of protein machineries encoded by two different genomes.
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Affiliation(s)
- Daiana N Moretti-Horten
- Center for Molecular Biology of Heidelberg University (ZMBH), DKFZ-ZMBH Alliance, 69120 Heidelberg, Germany; Institute of Biochemistry and Molecular Biology, ZBMZ, Faculty of Medicine, University of Freiburg, 79104 Freiburg, Germany; Faculty of Biology, University of Freiburg, 79104 Freiburg, Germany
| | - Carlotta Peselj
- Center for Molecular Biology of Heidelberg University (ZMBH), DKFZ-ZMBH Alliance, 69120 Heidelberg, Germany
| | - Asli Aras Taskin
- Institute of Biochemistry and Molecular Biology, ZBMZ, Faculty of Medicine, University of Freiburg, 79104 Freiburg, Germany
| | - Lisa Myketin
- Institute of Biochemistry and Molecular Biology, ZBMZ, Faculty of Medicine, University of Freiburg, 79104 Freiburg, Germany
| | - Uwe Schulte
- Institute of Physiology, Faculty of Medicine, University of Freiburg, 79104 Freiburg, Germany; CIBSS-Centre for Integrative Biological Signalling Studies, University of Freiburg, 79104 Freiburg, Germany
| | - Oliver Einsle
- Institut für Biochemie, University of Freiburg, 79104 Freiburg, Germany; BIOSS Centre for Biological Signalling Studies, University of Freiburg, 79104 Freiburg, Germany
| | - Friedel Drepper
- CIBSS-Centre for Integrative Biological Signalling Studies, University of Freiburg, 79104 Freiburg, Germany; BIOSS Centre for Biological Signalling Studies, University of Freiburg, 79104 Freiburg, Germany; Biochemistry & Functional Proteomics, Institute of Biology II, Faculty of Biology, University of Freiburg, 79104 Freiburg, Germany
| | - Marcin Luzarowski
- Core Facility for Mass Spectrometry and Proteomics, Center for Molecular Biology of Heidelberg University (ZMBH), DKFZ-ZMBH Alliance, 69120 Heidelberg, Germany
| | - F-Nora Vögtle
- Center for Molecular Biology of Heidelberg University (ZMBH), DKFZ-ZMBH Alliance, 69120 Heidelberg, Germany; Institute of Biochemistry and Molecular Biology, ZBMZ, Faculty of Medicine, University of Freiburg, 79104 Freiburg, Germany; CIBSS-Centre for Integrative Biological Signalling Studies, University of Freiburg, 79104 Freiburg, Germany; Network Aging Research, Heidelberg University, 69120 Heidelberg, Germany.
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3
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Khandwala CB, Sarkar P, Schmidt HB, Ma M, Kinnebrew M, Pusapati GV, Patel BB, Tillo D, Lebensohn AM, Rohatgi R. Direct ionic stress sensing and mitigation by the transcription factor NFAT5. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.09.23.559074. [PMID: 37886503 PMCID: PMC10602047 DOI: 10.1101/2023.09.23.559074] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/28/2023]
Abstract
Homeostatic control of intracellular ionic strength is essential for protein, organelle and genome function, yet mechanisms that sense and enable adaptation to ionic stress remain poorly understood in animals. We find that the transcription factor NFAT5 directly senses solution ionic strength using a C-terminal intrinsically disordered region. Both in intact cells and in a purified system, NFAT5 forms dynamic, reversible biomolecular condensates in response to increasing ionic strength. This self-associative property, conserved from insects to mammals, allows NFAT5 to accumulate in the nucleus and activate genes that restore cellular ion content. Mutations that reduce condensation or those that promote aggregation both reduce NFAT5 activity, highlighting the importance of optimally tuned associative interactions. Remarkably, human NFAT5 alone is sufficient to reconstitute a mammalian transcriptional response to ionic or hypertonic stress in yeast. Thus NFAT5 is both the sensor and effector of a cell-autonomous ionic stress response pathway in animal cells.
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Affiliation(s)
- Chandni B. Khandwala
- Departments of Biochemistry and Medicine, Stanford University School of Medicine, Stanford, CA 94305, USA
| | - Parijat Sarkar
- Departments of Biochemistry and Medicine, Stanford University School of Medicine, Stanford, CA 94305, USA
| | - H. Broder Schmidt
- Departments of Biochemistry and Medicine, Stanford University School of Medicine, Stanford, CA 94305, USA
| | - Mengxiao Ma
- Departments of Biochemistry and Medicine, Stanford University School of Medicine, Stanford, CA 94305, USA
| | - Maia Kinnebrew
- Departments of Biochemistry and Medicine, Stanford University School of Medicine, Stanford, CA 94305, USA
| | - Ganesh V. Pusapati
- Departments of Biochemistry and Medicine, Stanford University School of Medicine, Stanford, CA 94305, USA
| | - Bhaven B. Patel
- Departments of Biochemistry and Medicine, Stanford University School of Medicine, Stanford, CA 94305, USA
| | - Desiree Tillo
- Center for Cancer Research Genomics Core, National Cancer Institute, National Institutes of Health, NIH, Building 37, RM 2056B, Bethesda, MD, 20892, USA
| | - Andres M. Lebensohn
- Laboratory of Cellular and Molecular Biology, Center for Cancer Research, National Cancer Institute, National Institutes of Health, NIH, Building 37, RM 2056B, Bethesda, MD, 20892, USA
| | - Rajat Rohatgi
- Departments of Biochemistry and Medicine, Stanford University School of Medicine, Stanford, CA 94305, USA
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4
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Chawla S, Ahmadpour D, Schneider KL, Kumar N, Fischbach A, Molin M, Nystrom T. Calcineurin stimulation by Cnb1p overproduction mitigates protein aggregation and α-synuclein toxicity in a yeast model of synucleinopathy. Cell Commun Signal 2023; 21:220. [PMID: 37620860 PMCID: PMC10464345 DOI: 10.1186/s12964-023-01242-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2023] [Accepted: 07/22/2023] [Indexed: 08/26/2023] Open
Abstract
The calcium-responsive phosphatase, calcineurin, senses changes in Ca2+ concentrations in a calmodulin-dependent manner. Here we report that under non-stress conditions, inactivation of calcineurin signaling or deleting the calcineurin-dependent transcription factor CRZ1 triggered the formation of chaperone Hsp100p (Hsp104p)-associated protein aggregates in Saccharomyces cerevisiae. Furthermore, calcineurin inactivation aggravated α-Synuclein-related cytotoxicity. Conversely, elevated production of the calcineurin activator, Cnb1p, suppressed protein aggregation and cytotoxicity associated with the familial Parkinson's disease-related mutant α-Synuclein A53T in a partly CRZ1-dependent manner. Activation of calcineurin boosted normal localization of both wild type and mutant α-synuclein to the plasma membrane, an intervention previously shown to mitigate α-synuclein toxicity in Parkinson's disease models. The findings demonstrate that calcineurin signaling, and Ca2+ influx to the vacuole, limit protein quality control in non-stressed cells and may have implications for elucidating to which extent aberrant calcineurin signaling contributes to the progression of Parkinson's disease(s) and other synucleinopathies. Video Abstract.
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Affiliation(s)
- Srishti Chawla
- Institute for Biomedicine, Sahlgrenska Academy, Centre for Ageing and Health - AgeCap, University of Gothenburg, Gothenburg, 405 30, Sweden.
- Department of Life Sciences, Chalmers University of Technology, Gothenburg, Sweden.
| | - Doryaneh Ahmadpour
- Center for Bionics and Pain Research, Sahlgrenska University Hospital, Mölndal, 431 30, Sweden
| | - Kara L Schneider
- Institute for Biomedicine, Sahlgrenska Academy, Centre for Ageing and Health - AgeCap, University of Gothenburg, Gothenburg, 405 30, Sweden
| | - Navinder Kumar
- Institute for Biomedicine, Sahlgrenska Academy, Centre for Ageing and Health - AgeCap, University of Gothenburg, Gothenburg, 405 30, Sweden
| | - Arthur Fischbach
- Max Planck Institute for Biology of Ageing, Cologne, 50931, Germany
| | - Mikael Molin
- Department of Life Sciences, Chalmers University of Technology, Gothenburg, Sweden
| | - Thomas Nystrom
- Institute for Biomedicine, Sahlgrenska Academy, Centre for Ageing and Health - AgeCap, University of Gothenburg, Gothenburg, 405 30, Sweden.
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5
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Lee GM, Weng F, Cranley J, Rajasekhar A, Stoeckel M, Kane T, Tisi R, Wang Y. The Ycx1 protein encoded by the yeast YDL206W gene plays a role in calcium and calcineurin signaling. J Biol Chem 2023; 299:104647. [PMID: 36965615 PMCID: PMC10126930 DOI: 10.1016/j.jbc.2023.104647] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2022] [Revised: 03/03/2023] [Accepted: 03/17/2023] [Indexed: 03/27/2023] Open
Abstract
Calcium is ubiquitously present in all living cells and plays important regulatory roles in a wide variety of biological processes. In yeast, many effects of calcium are mediated via the action of calcineurin, a calcium/calmodulin-dependent protein phosphatase. Proper signaling of calcium and calcineurin is important in yeast, and the calcineurin pathway has emerged as a valuable target for developing novel antifungal drugs. Here, we report a role of YDL206W in calcium and calcineurin signaling in yeast. YDL206W is an uncharacterized gene in yeast, encoding a protein with two sodium/calcium exchange domains. Disrupting the YDL206W gene leads to a diminished level of calcium-induced activation of calcineurin and a reduced accumulation of cytosolic calcium. Consistent with a role of calcineurin in regulating pheromone and cell wall integrity signaling, the ydl206wΔ mutants display an enhanced growth arrest induced by pheromone treatment and poor growth at elevated temperature. Subcellular localization studies indicate that YDL206W is localized in endoplasmic reticulum and Golgi. Together, our results reveal YDL206W as a new regulator for calcineurin signaling in yeast and suggest a role of the endoplasmic reticulum and Golgi in regulating cytosolic calcium in yeast.
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Affiliation(s)
- Grace M Lee
- Department of Biology, Saint Louis University, St Louis, Missouri, USA
| | - Fangli Weng
- Department of Biology, Saint Louis University, St Louis, Missouri, USA
| | - Juliana Cranley
- Department of Biology, Saint Louis University, St Louis, Missouri, USA
| | | | - Matthew Stoeckel
- Department of Biology, Saint Louis University, St Louis, Missouri, USA
| | - Thomas Kane
- Department of Biology, Saint Louis University, St Louis, Missouri, USA
| | - Renata Tisi
- Department of Biotechnology and Bioscience, University of Milano-Bicocca, Milan, Italy
| | - Yuqi Wang
- Department of Biology, Saint Louis University, St Louis, Missouri, USA.
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6
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Peselj C, Ebrahimi M, Broeskamp F, Prokisch S, Habernig L, Alvarez-Guerra I, Kohler V, Vögtle FN, Büttner S. Sterol Metabolism Differentially Contributes to Maintenance and Exit of Quiescence. Front Cell Dev Biol 2022; 10:788472. [PMID: 35237594 PMCID: PMC8882848 DOI: 10.3389/fcell.2022.788472] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2021] [Accepted: 01/20/2022] [Indexed: 01/01/2023] Open
Abstract
Nutrient starvation initiates cell cycle exit and entry into quiescence, a reversible, non-proliferative state characterized by stress tolerance, longevity and large-scale remodeling of subcellular structures. Depending on the nature of the depleted nutrient, yeast cells are assumed to enter heterogeneous quiescent states with unique but mostly unexplored characteristics. Here, we show that storage and consumption of neutral lipids in lipid droplets (LDs) differentially impacts the regulation of quiescence driven by glucose or phosphate starvation. Upon prolonged glucose exhaustion, LDs were degraded in the vacuole via Atg1-dependent lipophagy. In contrast, yeast cells entering quiescence due to phosphate exhaustion massively over-accumulated LDs that clustered at the vacuolar surface but were not engulfed via lipophagy. Excessive LD biogenesis required contact formation between the endoplasmic reticulum and the vacuole at nucleus-vacuole junctions and was accompanied by a shift of the cellular lipid profile from membrane towards storage lipids, driven by a transcriptional upregulation of enzymes generating neutral lipids, in particular sterol esters. Importantly, sterol ester biogenesis was critical for long-term survival of phosphate-exhausted cells and supported rapid quiescence exit upon nutrient replenishment, but was dispensable for survival and regrowth of glucose-exhausted cells. Instead, these cells relied on de novo synthesis of sterols and fatty acids for quiescence exit and regrowth. Phosphate-exhausted cells efficiently mobilized storage lipids to support several rounds of cell division even in presence of inhibitors of fatty acid and sterol biosynthesis. In sum, our results show that neutral lipid biosynthesis and mobilization to support quiescence maintenance and exit is tailored to the respective nutrient scarcity.
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Affiliation(s)
- Carlotta Peselj
- Department of Molecular Biosciences, The Wenner-Gren Institute, Stockholm University, Stockholm, Sweden
| | - Mahsa Ebrahimi
- Department of Molecular Biosciences, The Wenner-Gren Institute, Stockholm University, Stockholm, Sweden
| | - Filomena Broeskamp
- Department of Molecular Biosciences, The Wenner-Gren Institute, Stockholm University, Stockholm, Sweden
| | - Simon Prokisch
- Department of Molecular Biosciences, The Wenner-Gren Institute, Stockholm University, Stockholm, Sweden
| | - Lukas Habernig
- Department of Molecular Biosciences, The Wenner-Gren Institute, Stockholm University, Stockholm, Sweden
| | - Irene Alvarez-Guerra
- Department of Molecular Biosciences, The Wenner-Gren Institute, Stockholm University, Stockholm, Sweden
| | - Verena Kohler
- Department of Molecular Biosciences, The Wenner-Gren Institute, Stockholm University, Stockholm, Sweden
| | - F.-Nora Vögtle
- Center for Molecular Biology of Heidelberg University (ZMBH), DKFZ-ZMBH Alliance, Heidelberg University, Heidelberg, Germany
- Network Aging Research, Heidelberg University, Heidelberg, Germany
- CIBSS - Centre for Integrative Biological Signalling Studies, University of Freiburg, Freiburg, Germany
| | - Sabrina Büttner
- Department of Molecular Biosciences, The Wenner-Gren Institute, Stockholm University, Stockholm, Sweden
- Institute of Molecular Biosciences, University of Graz, Graz, Austria
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7
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Habernig L, Broeskamp F, Aufschnaiter A, Diessl J, Peselj C, Urbauer E, Eisenberg T, de Ory A, Büttner S. Ca2+ administration prevents α-synuclein proteotoxicity by stimulating calcineurin-dependent lysosomal proteolysis. PLoS Genet 2021; 17:e1009911. [PMID: 34780474 PMCID: PMC8629384 DOI: 10.1371/journal.pgen.1009911] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2021] [Revised: 11/29/2021] [Accepted: 10/25/2021] [Indexed: 12/02/2022] Open
Abstract
The capacity of a cell to maintain proteostasis progressively declines during aging. Virtually all age-associated neurodegenerative disorders associated with aggregation of neurotoxic proteins are linked to defects in the cellular proteostasis network, including insufficient lysosomal hydrolysis. Here, we report that proteotoxicity in yeast and Drosophila models for Parkinson's disease can be prevented by increasing the bioavailability of Ca2+, which adjusts intracellular Ca2+ handling and boosts lysosomal proteolysis. Heterologous expression of human α-synuclein (αSyn), a protein critically linked to Parkinson's disease, selectively increases total cellular Ca2+ content, while the levels of manganese and iron remain unchanged. Disrupted Ca2+ homeostasis results in inhibition of the lysosomal protease cathepsin D and triggers premature cellular and organismal death. External administration of Ca2+ reduces αSyn oligomerization, stimulates cathepsin D activity and in consequence restores survival, which critically depends on the Ca2+/calmodulin-dependent phosphatase calcineurin. In flies, increasing the availability of Ca2+ discloses a neuroprotective role of αSyn upon manganese overload. In sum, we establish a molecular interplay between cathepsin D and calcineurin that can be activated by Ca2+ administration to counteract αSyn proteotoxicity.
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Affiliation(s)
- Lukas Habernig
- Department of Molecular Biosciences, The Wenner-Gren Institute, Stockholm University, Stockholm, Sweden
| | - Filomena Broeskamp
- Department of Molecular Biosciences, The Wenner-Gren Institute, Stockholm University, Stockholm, Sweden
| | - Andreas Aufschnaiter
- Department of Biochemistry and Biophysics, Stockholm University, Stockholm, Sweden
| | - Jutta Diessl
- Department of Molecular Biosciences, The Wenner-Gren Institute, Stockholm University, Stockholm, Sweden
| | - Carlotta Peselj
- Department of Molecular Biosciences, The Wenner-Gren Institute, Stockholm University, Stockholm, Sweden
| | - Elisabeth Urbauer
- Department of Molecular Biosciences, The Wenner-Gren Institute, Stockholm University, Stockholm, Sweden
| | - Tobias Eisenberg
- Institute of Molecular Biosciences, University of Graz, Graz, Austria
- BioTechMed Graz, Graz, Austria
- Field of Excellence BioHealth–University of Graz, Graz, Austria
| | - Ana de Ory
- Department of Molecular Biosciences, The Wenner-Gren Institute, Stockholm University, Stockholm, Sweden
| | - Sabrina Büttner
- Department of Molecular Biosciences, The Wenner-Gren Institute, Stockholm University, Stockholm, Sweden
- Institute of Molecular Biosciences, University of Graz, Graz, Austria
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8
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Moro S, Moscoso-Romero E, Poddar A, Mulet JM, Perez P, Chen Q, Valdivieso MH. Exomer Is Part of a Hub Where Polarized Secretion and Ionic Stress Connect. Front Microbiol 2021; 12:708354. [PMID: 34349749 PMCID: PMC8326576 DOI: 10.3389/fmicb.2021.708354] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2021] [Accepted: 06/18/2021] [Indexed: 11/13/2022] Open
Abstract
Plasma membrane and membranous organelles contribute to the physiology of the Eukaryotic cell by participating in vesicle trafficking and the maintenance of ion homeostasis. Exomer is a protein complex that facilitates vesicle transport from the trans-Golgi network to the plasma membrane, and its absence leads to the retention of a set of selected cargoes in this organelle. However, this retention does not explain all phenotypes observed in exomer mutants. The Schizosaccharomyces pombe exomer is composed of Cfr1 and Bch1, and cfr1Δ and bch1Δ were sensitive to high concentrations of potassium salts but not sorbitol, which showed sensitivity to ionic but not osmotic stress. Additionally, the activity of the plasma membrane ATPase was higher in exomer mutants than in the wild-type, pointing to membrane hyperpolarization, which caused an increase in intracellular K+ content and mild sensitivity to Na+, Ca2+, and the aminoglycoside antibiotic hygromycin B. Moreover, in response to K+ shock, the intracellular Ca2+ level of cfr1Δ cells increased significantly more than in the wild-type, likely due to the larger Ca2+ spikes in the mutant. Microscopy analyses showed a defective endosomal morphology in the mutants. This was accompanied by an increase in the intracellular pools of the K+ exporting P-type ATPase Cta3 and the plasma membrane Transient Receptor Potential (TRP)-like Ca2+ channel Pkd2, which were partially diverted from the trans-Golgi network to the prevacuolar endosome. Despite this, most Cta3 and Pkd2 were delivered to the plasma membrane at the cell growing sites, showing that their transport from the trans-Golgi network to the cell surface occurred in the absence of exomer. Nevertheless, shortly after gene expression in the presence of KCl, the polarized distribution of Cta3 and Pkd2 in the plasma membrane was disturbed in the mutants. Finally, the use of fluorescent probes suggested that the distribution and dynamics of association of some lipids to the plasma membrane in the presence of KCl were altered in the mutants. Thus, exomer participation in the response to K+ stress was multifaceted. These results supported the notion that exomer plays a general role in protein sorting at the trans-Golgi network and in polarized secretion, which is not always related to a function as a selective cargo adaptor.
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Affiliation(s)
- Sandra Moro
- Instituto de Biología Funcional y Genómica, Consejo Superior de Investigaciones Científicas, Salamanca, Spain.,Departamento de Microbiología y Genética, Universidad de Salamanca, Salamanca, Spain
| | - Esteban Moscoso-Romero
- Instituto de Biología Funcional y Genómica, Consejo Superior de Investigaciones Científicas, Salamanca, Spain.,Departamento de Microbiología y Genética, Universidad de Salamanca, Salamanca, Spain
| | - Abhishek Poddar
- Department of Biological Sciences, University of Toledo, Toledo, OH, United States
| | - Jose M Mulet
- Instituto de Biología Molecular y Celular de Plantas, Universitat Politècnica de València-Consejo Superior de Investigaciones Científicas, Valencia, Spain
| | - Pilar Perez
- Instituto de Biología Funcional y Genómica, Consejo Superior de Investigaciones Científicas, Salamanca, Spain
| | - Qian Chen
- Department of Biological Sciences, University of Toledo, Toledo, OH, United States
| | - M-Henar Valdivieso
- Instituto de Biología Funcional y Genómica, Consejo Superior de Investigaciones Científicas, Salamanca, Spain.,Departamento de Microbiología y Genética, Universidad de Salamanca, Salamanca, Spain
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