scholarly journals Rsp5 ubiquitin ligase affects isoprenoid pathway and cell wall organization in S. cerevisiae.

2005 ◽  
Vol 52 (1) ◽  
pp. 207-220 ◽  
Author(s):  
Joanna Kamińska ◽  
Marta Kwapisz ◽  
Kariona Grabińska ◽  
Jacek Orłowski ◽  
Magdalena Boguta ◽  
...  
Keyword(s):  
Cell Wall ◽  
Plasma Membrane ◽  
Protein Glycosylation ◽  
Cell Wall Integrity ◽  
Wall Structure ◽  
Ergosterol Biosynthesis ◽  
Calcofluor White ◽  
Isoprenoid Pathway ◽  
Dimethylallyl Diphosphate ◽  
Key Enzyme

Dimethylallyl diphosphate, an isomer of isopentenyl diphosphate, is a common substrate of Mod5p, a tRNA modifying enzyme, and the farnesyl diphosphate synthase Erg20p, the key enzyme of the isoprenoid pathway. rsp5 mutants, defective in the Rsp5 ubiquitin-protein ligase, were isolated and characterized as altering the mitochondrial/cytosolic distribution of Mod5p. To understand better how competition for the substrate determines the regulation at the molecular level, we analyzed the effect of the rsp5-13 mutation on Erg20p expression. The level of Erg20p was three times lower in rsp5-13 compared to the wild type strain and this effect was dependent on active Mod5p. Northern blot analysis indicated a regulatory role of Rsp5p in ERG20 transcription. ERG20 expression was also impaired in pkc1Delta lacking a component of the cell wall integrity signaling pathway. Low expression of Erg20p in rsp5 cells was accompanied by low level of ergosterol, the main end product of the isoprenoid pathway. Additionally, rsp5 strains were resistant to nystatin, which binds to ergosterol present in the plasma membrane, and sensitive to calcofluor white, a drug destabilizing cell wall integrity by binding to chitin. Furthermore, the cell wall structure appeared abnormal in most rsp5-13 cells investigated by electron microscopy and chitin level in the cell wall was increased two-fold. These results indicate that Rsp5p affects the isoprenoid pathway which has important roles in ergosterol biosynthesis, protein glycosylation and transport and in this way may influence the composition of the plasma membrane and cell wall.

scholarly journals Up against the Wall: Is Yeast Cell Wall Integrity Ensured by Mechanosensing in Plasma Membrane Microdomains?

2014 ◽  
Vol 81 (3) ◽  
pp. 806-811 ◽  
Author(s):  
Christian Kock ◽  
Yves F. Dufrêne ◽  
Jürgen J. Heinisch
Keyword(s):  
Cell Wall ◽  
Plasma Membrane ◽  
Yeast Cell ◽  
Antifungal Drugs ◽  
Cell Wall Integrity ◽  
Yeast Cell Wall ◽  
Membrane Microdomains ◽  
Wall Structure ◽  
Fungal Cell ◽  
Membrane Spanning

ABSTRACTYeast cell wall integrity (CWI) signaling serves as a model of the regulation of fungal cell wall synthesis and provides the basis for the development of antifungal drugs. A set of five membrane-spanning sensors (Wsc1 to Wsc3, Mid2, and Mtl1) detect cell surface stress and commence the signaling pathway upon perturbations of either the cell wall structure or the plasma membrane. We here summarize the latest advances in the structure/function relationship primarily of the Wsc1 sensor and critically review the evidence that it acts as a mechanosensor. The relevance and physiological significance of the information obtained for the function of the other CWI sensors, as well as expected future developments, are discussed.

scholarly journals Curcumin Targets Cell Wall Integrity via Calcineurin-Mediated Signaling in Candida albicans

2013 ◽  
Vol 58 (1) ◽  
pp. 167-175 ◽  
Author(s):  
Awanish Kumar ◽  
Sanjiveeni Dhamgaye ◽  
Indresh Kumar Maurya ◽  
Ashutosh Singh ◽  
Monika Sharma ◽  
...  
Keyword(s):  
Cell Wall ◽  
Candida Albicans ◽  
Critical Role ◽  
Pathogenic Fungi ◽  
Cell Wall Integrity ◽  
Ergosterol Biosynthesis ◽  
Ros Generation ◽  
Calcofluor White ◽  
Content Type ◽  
Cell Wall Damage

ABSTRACTCurcumin (CUR) shows antifungal activity against a range of pathogenic fungi, includingCandida albicans. The reported mechanisms of action of CUR include reactive oxygen species (ROS) generation, defects in the ergosterol biosynthesis pathway, decrease in hyphal development, and modulation of multidrug efflux pumps. Reportedly, each of these pathways is independently linked to the cell wall machinery inC. albicans, but surprisingly, CUR has not been previously implicated in cell wall damage. In the present study, we performed transcriptional profiling to identify the yet-unidentified targets of CUR inC. albicans. We found that, among 348 CUR-affected genes, 51 were upregulated and 297 were downregulated. Interestingly, most of the cell wall integrity pathway genes were downregulated. The possibility of the cell wall playing a critical role in the mechanism of CUR required further validation; therefore, we performed specific experiments to establish if there was any link between the two. The fractional inhibitory concentration index values of 0.24 to 0.37 show that CUR interacts synergistically with cell wall-perturbing (CWP) agents (caspofungin, calcofluor white, Congo red, and SDS). Furthermore, we could observe cell wall damage and membrane permeabilization by CUR alone, as well as synergistically with CWP agents. We also found hypersusceptibility in calcineurin and mitogen-activated protein (MAP) kinase pathway mutants against CUR, which confirmed that CUR also targets cell wall biosynthesis inC. albicans. Together, these data provide strong evidence that CUR disrupts cell wall integrity inC. albicans. This new information on the mechanistic action of CUR could be employed in improving treatment strategies and in combinatorial drug therapy.

scholarly journals Hechtian Strands Transmit Cell Wall Integrity Signals in Plant Cells

Plants ◽  
2020 ◽  
Vol 9 (5) ◽  
pp. 604
Author(s):  
Arata Yoneda ◽  
Misato Ohtani ◽  
Daisuke Katagiri ◽  
Yoichiroh Hosokawa ◽  
Taku Demura
Keyword(s):  
Cell Wall ◽  
Plasma Membrane ◽  
Femtosecond Laser ◽  
Cell Morphology ◽  
Laser Microdissection ◽  
Plant Cells ◽  
Laser Pulses ◽  
Femtosecond Laser Pulses ◽  
Cell Wall Integrity ◽  
Calcofluor White

Hechtian strands are thread-like structures in plasmolyzed plant cells that connect the cell wall to the plasma membrane. Although these strands were first observed more than 100 years ago, their physiological roles are largely unknown. Here, we used intracellular laser microdissection to examine the effects of disrupting Hechtian strands on plasmolyzed tobacco BY-2 cells. When we focused femtosecond laser pulses on Hechtian strands, targeted disruptions were induced, but no visible changes in cell morphology were detected. However, the calcofluor white signals from β-glucans was detected in plasmolyzed cells with disrupted Hechtian strands, whereas no signals were detected in untreated plasmolyzed cells. These results suggest that Hechtian strands play roles in sensing cell wall integrity.

scholarly journals The Candida albicans Sur7 Protein Is Needed for Proper Synthesis of the Fibrillar Component of the Cell Wall That Confers Strength

2010 ◽  
Vol 10 (1) ◽  
pp. 72-80 ◽  
Author(s):  
Hong X. Wang ◽  
Lois M. Douglas ◽  
Vishukumar Aimanianda ◽  
Jean-Paul Latgé ◽  
James B. Konopka
Keyword(s):  
Cell Wall ◽  
Candida Albicans ◽  
Plasma Membrane ◽  
Wall Structure ◽  
Cell Wall Synthesis ◽  
Calcofluor White ◽  
Content Type ◽  
Membrane Compartment ◽  
Fibrillar Component ◽  
And Function

ABSTRACTTheCandida albicansplasma membrane plays important roles in interfacing with the environment, morphogenesis, and cell wall synthesis. The role of the Sur7 protein in cell wall structure and function was analyzed, since previous studies showed that this plasma membrane protein is needed to prevent abnormal intracellular growth of the cell wall. Sur7 localizes to stable patches in the plasma membrane, known as MCC (membrane compartment occupied by Can1), that are associated with eisosome proteins. Thesur7Δ mutant cells displayed increased sensitivity to factors that exacerbate cell wall defects, such as detergent (SDS) and the chitin-binding agents calcofluor white and Congo red. Thesur7Δ cells were also slightly more sensitive to inhibitors that block the synthesis of cell wall chitin (nikkomycin Z) and β-1,3-glucan (caspofungin). In contrast, Fmp45, a paralog of Sur7 that also localizes to punctate plasma membrane patches, did not have a detectable role in cell wall synthesis. Chemical analysis of cell wall composition demonstrated thatsur7Δ cells contain decreased levels of β-glucan, a glucose polymer that confers rigidity on the cell wall. Consistent with this,sur7Δ cells were more sensitive to lysis, which could be partially rescued by increasing the osmolarity of the medium. Interestingly, Sur7 is present in static patches, whereas β-1,3-glucan synthase is mobile in the plasma membrane and is often associated with actin patches. Thus, Sur7 may influence β-glucan synthesis indirectly, perhaps by altering the functions of the cell signaling components that localize to the MCC and eisosome domains.

scholarly journals Yeast Nap1-Binding Protein Nbp2p Is Required for Mitotic Growth at High Temperatures and for Cell Wall Integrity

Genetics ◽  
2003 ◽  
Vol 165 (2) ◽  
pp. 517-529
Author(s):  
Kentaro Ohkuni ◽  
Asuko Okuda ◽  
Akihiko Kikuchi
Keyword(s):  
Cell Death ◽  
Cell Wall ◽  
High Temperature ◽  
High Temperatures ◽  
Hybrid System ◽  
Mapk Pathway ◽  
Binding Protein ◽  
Cell Wall Integrity ◽  
Calcofluor White ◽  
Two Hybrid

AbstractNbp2p is a Nap1-binding protein in Saccharomyces cerevisiae identified by its interaction with Nap1 by a two-hybrid system. NBP2 encodes a novel protein consisting of 236 amino acids with a Src homology 3 (SH3) domain. We showed that NBP2 functions to promote mitotic cell growth at high temperatures and cell wall integrity. Loss of Nbp2 results in cell death at high temperatures and in sensitivity to calcofluor white. Cell death at high temperature is thought not to be due to a weakened cell wall. Additionally, we have isolated several type-2C serine threonine protein phosphatases (PTCs) as multicopy suppressors and MAP kinase-kinase (MAPKK), related to the yeast PKC MAPK pathway, as deletion suppressors of the nbp2Δ mutant. Screening for deletion suppressors is a new genetic approach to identify and characterize additional proteins in the Nbp2-dependent pathway. Genetic analyses suggested that Ptc1, which interacts with Nbp2 by the two-hybrid system, acts downstream of Nbp2 and that cells lacking the function of Nbp2 prefer to lose Mkk1, but the PKC MAPK pathway itself is indispensable when Nbp2 is deleted at high temperature.

scholarly journals Putative PmrA and PmcA are important for normal growth, morphogenesis and cell wall integrity, but not for viability in Aspergillus nidulans

Microbiology ◽  
2014 ◽  
Vol 160 (11) ◽  
pp. 2387-2395 ◽  
Author(s):  
Hechun Jiang ◽  
Feifei Liu ◽  
Shizhu Zhang ◽  
Ling Lu
Keyword(s):  
Cell Wall ◽  
Plasma Membrane ◽  
Aspergillus Nidulans ◽  
Normal Growth ◽  
Cell Wall Integrity ◽  
Plasma Membrane Atpase ◽  
Growth Defects ◽  
Double Deletion ◽  
Intracellular Ca ◽  
P Type

P-type Ca2+-transporting ATPases are Ca2+ pumps, extruding cytosolic Ca2+ to the extracellular environment or the intracellular Ca2+ store lumens. In budding yeast, Pmr1 (plasma membrane ATPase related), and Pmc1 (plasma membrane calcium-ATPase) cannot be deleted simultaneously for it to survive in standard medium. Here, we deleted two putative Ca2+ pumps, designated AnPmrA and AnPmcA, from Aspergillus nidulans, and obtained the mutants ΔanpmrA and ΔanpmcA, respectively. Then, using ΔanpmrA as the starting strain, the promoter of its anpmcA was replaced with the alcA promoter to secure the mutant ΔanpmrAalcApmcA or its anpmcA was deleted completely to produce the mutant ΔanpmrAΔpmcA. Different from the case in Saccharomyces cerevisiae, double deletion of anpmrA and anpmcA was not lethal in A. nidulans. In addition, deletion of anpmrA and/or anpmcA had produced growth defects, although overexpression of AnPmc1 in ΔanpmrAalcApmcA could not restore the growth defects that resulted from the loss of AnPmrA. Moreover, we found AnPmrA was indispensable for maintenance of normal morphogenesis, especially in low-Ca2+/Mn2+ environments. Thus, our findings suggest AnPmrA and AnPmcA might play important roles in growth, morphogenesis and cell wall integrity in A. nidulans in a different way from that in yeasts.

scholarly journals Yeast cell wall integrity sensors form specific plasma membrane microdomains important for signalling

2016 ◽  
Vol 18 (9) ◽  
pp. 1251-1267 ◽  
Author(s):  
Christian Kock ◽  
Henning Arlt ◽  
Christian Ungermann ◽  
Jürgen J. Heinisch
Keyword(s):  
Cell Wall ◽  
Plasma Membrane ◽  
Yeast Cell ◽  
Cell Wall Integrity ◽  
Yeast Cell Wall ◽  
Membrane Microdomains ◽  
Plasma Membrane Microdomains

The Candida albicans pH-regulated KER1 gene encodes a lysine/glutamic-acid-rich plasma-membrane protein that is involved in cell aggregation

Microbiology ◽  
2004 ◽  
Vol 150 (8) ◽  
pp. 2641-2651 ◽  
Author(s):  
Amparo Galán ◽  
Manuel Casanova ◽  
Amelia Murgui ◽  
Donna M. MacCallum ◽  
Frank C. Odds ◽  
...  
Keyword(s):  
Cell Wall ◽  
Candida Albicans ◽  
Plasma Membrane ◽  
Glutamic Acid ◽  
Germ Tube ◽  
Cell Surface Hydrophobicity ◽  
Cell Aggregation ◽  
Surface Hydrophobicity ◽  
Amino Acid Sequences ◽  
Calcofluor White

Immunoscreening of a Candida albicans cDNA library with a polyclonal germ-tube-specific antibody (pAb anti-gt) resulted in the isolation of a gene encoding a lysine/glutamic-acid-rich protein, which was consequently designated KER1. The nucleotide and deduced amino acid sequences of this gene displayed no significant homology with any other known sequence. KER1 encodes a 134 kDa lysine (14·5 %)/glutamic acid (16·7 %) protein (Ker1p) that contains two potential transmembrane segments. KER1 was expressed in a pH-conditional manner, with maximal expression at alkaline pH and lower expression at pH 4·0, and was regulated by RIM101. A Δker1/Δker1 null mutant grew normally but was hyperflocculant under germ-tube-inducing conditions, yet this behaviour was also observed in stationary-phase cells grown under other incubation conditions. Western blotting analysis of different subcellular fractions, using as a probe a monospecific polyclonal antibody raised against a highly antigenic domain of Ker1p (pAb anti-Ker1p), revealed the presence of a 134 kDa band in the purified plasma-membrane fraction from the wild-type strain that was absent in the homologous preparation from Δker1/Δker1 mutant. The pattern of cell-wall protein and mannoprotein species released by digestion with β-glucanases, reactive towards pAbs anti-gt and anti-Ker1p, as well as against concanavalin A, was also different in the Δker1/Δker1 mutant. Mutant strains also displayed an increased cell-surface hydrophobicity and sensitivity to Congo red and Calcofluor white. Overall, these findings indicate that the mutant strain was affected in cell-wall composition and/or structure. The fact that the ker1 mutant had attenuated virulence in systemic mouse infections suggests that this surface protein is also important in host–fungus interactions.

scholarly journals Wood Cell-Wall Structure Requires Local 2D-Microtubule Disassembly by a Novel Plasma Membrane-Anchored Protein

2010 ◽  
Vol 20 (13) ◽  
pp. 1197-1202 ◽  
Author(s):  
Yoshihisa Oda ◽  
Yuki Iida ◽  
Yuki Kondo ◽  
Hiroo Fukuda
Keyword(s):  
Cell Wall ◽  
Plasma Membrane ◽  
Wood Cell Wall ◽  
Cell Wall Structure ◽  
Wall Structure
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