Plant PIEZO homologs modulate vacuole morphology during tip growth

Science ◽  
2021 ◽  
Vol 373 (6554) ◽  
pp. 586-590
Author(s):  
Ivan Radin ◽  
Ryan A. Richardson ◽  
Joshua H. Coomey ◽  
Ethan R. Weiner ◽  
Carlisle S. Bascom ◽  
...  
Keyword(s):  
Plasma Membrane ◽  
Tip Growth ◽  
Plant Cells ◽  
Normal Growth ◽  
Calcium Oscillations ◽  
Flowering Plant ◽  
Cytoplasmic Calcium ◽  
Loss Of Function ◽  
Freedom Of Movement ◽  
Vacuolar Membranes

In animals, PIEZOs are plasma membrane–localized cation channels involved in diverse mechanosensory processes. We investigated PIEZO function in tip-growing cells in the moss Physcomitrium patens and the flowering plant Arabidopsis thaliana. PpPIEZO1 and PpPIEZO2 redundantly contribute to the normal growth, size, and cytoplasmic calcium oscillations of caulonemal cells. Both PpPIEZO1 and PpPIEZO2 localized to vacuolar membranes. Loss-of-function, gain-of-function, and overexpression mutants revealed that moss PIEZO homologs promote increased complexity of vacuolar membranes through tubulation, internalization, and/or fission. Arabidopsis PIEZO1 also localized to the tonoplast and is required for vacuole tubulation in the tips of pollen tubes. We propose that in plant cells the tonoplast has more freedom of movement than the plasma membrane, making it a more effective location for mechanosensory proteins.

scholarly journals AtRBOHC/RHD2 vesicular delivery to the apical plasma membrane domain during root hair development

2021 ◽  
Author(s):  
Lenka Kuběnová ◽  
Michaela Tichá ◽  
Jozef Šamaj ◽  
Miroslav Ovečka
Keyword(s):  
Plasma Membrane ◽  
Quantitative Analysis ◽  
Root Hair ◽  
Tip Growth ◽  
Root Hairs ◽  
Apical Plasma Membrane ◽  
Loss Of Function ◽  
Short Root ◽  
Early Endosomes ◽  
Root Hair Initiation

AbstractArabidopsis root hairs develop as long tubular extensions from the rootward pole of trichoblasts and exert polarized tip growth. The establishment and maintenance of root hair polarity is a complex process involving the local apical production of reactive oxygen species (ROS) generated by NADPH oxidase RESPIRATORY BURST OXIDASE HOMOLOG PROTEIN C/ROOT HAIR DEFECTIVE 2 (AtRBOHC/RHD2). It has been shown that loss-of-function rhd2 mutants have short root hairs that are unable to elongate by tip growth, and this phenotype was fully complemented by GFP-RHD2 expressed under the RHD2 promoter. However, the spatiotemporal mechanism of AtRBOHC/RHD2 subcellular redistribution and delivery to the plasma membrane (PM) during root hair initiation and tip growth are still unclear. Here, we used advanced microscopy for detailed qualitative and quantitative analysis of vesicular compartments containing GFP-RHD2 and characterization of their movements in developing bulges and growing root hairs. These compartments, identified by an independent marker such as the trans-Golgi network (TGN), deliver GFP-RHD2 to the apical PM domain, the extent of which correlates with the stage of root hair formation. Movements of TGN/early endosomes, but not late endosomes, were affected in the bulging domains of the rhd2-1 mutant. Finally, we reveal that accumulation in the growing tip, docking, and incorporation of TGN compartments containing GFP-RHD2 to the apical PM of root hairs requires structural sterols. These results help clarify the mechanism of polarized AtRBOHC/RHD2 targeting, maintenance, and recycling at the apical PM domain, coordinated with different developmental stages of root hair initiation and growth.One-sentence summaryAdvanced microscopy and quantitative analysis of vesicular TGN compartments revealed that delivering GFP-RHD2 to the apical plasma membrane domains of developing bulges and growing root hairs requires structural sterols.

scholarly journals Regulation of Vacuole Morphology by PIEZO Channels in Spreading Earth Moss

2020 ◽  
Author(s):  
Ivan Radin ◽  
Ryan A. Richardson ◽  
Ethan R. Weiner ◽  
Carlisle S. Bascom ◽  
Magdalena Bezanilla ◽  
...  
Keyword(s):  
Fundamental Property ◽  
Normal Growth ◽  
Land Plant ◽  
Loss Of Function ◽  
Cellular Mechanics ◽  
Hypoosmotic Shock ◽  
Piezo Channels ◽  
Vacuolar Membranes ◽  
Shock Loss ◽  
Green Lineage

AbstractThe perception of mechanical force is a fundamental property of most, if not all cells. PIEZO channels are plasma membrane-embedded mechanosensitive calcium channels that play diverse and essential roles in mechanobiological processes in animals1,2. PIEZO channel homologs are found in plants3,4, but their role(s) in the green lineage are almost completely unknown. Plants and animals diverged approximately 1.5 billion years ago, independently evolved multicellularity, and have vastly different cellular mechanics5. Here, we investigate PIEZO channel function in the moss Physcomitrium patens, a representative of one of the first land plant lineages. PpPIEZO1 and PpPIEZO2 were redundantly required for normal growth, size, and shape of tip-growing caulonema cells. Both were localized to vacuolar membranes and facilitated the release of calcium into the cytosol in response to hypoosmotic shock. Loss-of-function (ΔPppiezo1/2) and gain-of-function (PpPIEZO2-R2508K and -R2508H) mutants revealed a role for moss PIEZO homologs in regulating vacuole morphology. Our work here shows that plant and animal PIEZO homologs have diverged in both subcellular localization and in function, likely co-opted to serve different needs in each lineage. The plant homologs of PIEZO channels thus provide a compelling lens through which to study plant mechanobiology and the evolution of mechanoperceptive strategies in multicellular eukaryotes.

Enrichment of vitronectin- and fibronectin-like proteins in NaCI-adapted plant cells and evidence for their involvement in plasma membrane-cell wall adhesion

1993 ◽  
Vol 3 (5) ◽  
pp. 637-646 ◽  
Author(s):  
Jian-Kang Zhu ◽  
Jun Shi ◽  
Utpal Singh ◽  
Sarah E. Wyatt ◽  
Ray A. Bressan ◽  
...  
Keyword(s):  
Cell Wall ◽  
Plasma Membrane ◽  
Plant Cells ◽  
Membrane Cell

scholarly journals Fig mosaic emaravirus p4 protein is involved in cell-to-cell movement

2013 ◽  
Vol 94 (3) ◽  
pp. 682-686 ◽  
Author(s):  
Kazuya Ishikawa ◽  
Kensaku Maejima ◽  
Ken Komatsu ◽  
Osamu Netsu ◽  
Takuya Keima ◽  
...  
Keyword(s):  
Plasma Membrane ◽  
Laser Scanning ◽  
Movement Protein ◽  
Rna Virus ◽  
Cell Movement ◽  
Plant Cells ◽  
Laser Scanning Microscopy ◽  
Confocal Laser ◽  
Series Of Experiments ◽  
Fig Mosaic Virus

Fig mosaic virus (FMV), a member of the newly formed genus Emaravirus, is a segmented negative-strand RNA virus. Each of the six genomic FMV segments contains a single ORF: that of RNA4 encodes the protein p4. FMV-p4 is presumed to be the movement protein (MP) of the virus; however, direct experimental evidence for this is lacking. We assessed the intercellular distribution of FMV-p4 in plant cells by confocal laser scanning microscopy and we found that FMV-p4 was localized to plasmodesmata and to the plasma membrane accompanied by tubule-like structures. A series of experiments designed to examine the movement functions revealed that FMV-p4 has the capacity to complement viral cell-to-cell movement, prompt GFP diffusion between cells, and spread by itself to neighbouring cells. Altogether, our findings demonstrated that FMV-p4 shares several properties with other viral MPs and plays an important role in cell-to-cell movement.

scholarly journals Stablization of ACOs by NatB mediated N-terminal acetylation is required for ethylene homeostasis

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Hai-qing Liu ◽  
Ya-jie Zou ◽  
Xiao-feng Li ◽  
Lei Wu ◽  
Guang-qin Guo
Keyword(s):  
Protein Modification ◽  
Normal Growth ◽  
Ethylene Biosynthesis ◽  
Regulation Mechanism ◽  
Biological Functions ◽  
Loss Of Function ◽  
Auxiliary Subunit ◽  
Ethylene Content ◽  
Endogenous Ethylene ◽  
Exogenous Ethylene

AbstractN-terminal acetylation (NTA) is a highly abundant protein modification catalyzed by N-terminal acetyltransferases (NATs) in eukaryotes. However, the plant NATs and their biological functions have been poorly explored. Here we reveal that loss of function of CKRC3 and NBC-1, the auxiliary subunit (Naa25) and catalytic subunit (Naa20) of Arabidopsis NatB, respectively, led to defects in skotomorphogenesis and triple responses of ethylene. Proteome profiling and WB test revealed that the 1-amincyclopropane-1-carboxylate oxidase (ACO, catalyzing the last step of ethylene biosynthesis pathway) activity was significantly down-regulated in natb mutants, leading to reduced endogenous ethylene content. The defective phenotypes could be fully rescued by application of exogenous ethylene, but less by its precursor ACC. The present results reveal a previously unknown regulation mechanism at the co-translational protein level for ethylene homeostasis, in which the NatB-mediated NTA of ACOs render them an intracellular stability to maintain ethylene homeostasis for normal growth and responses.

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 Resistance to miltefosine results from amplification of the RTA3 floppase or inactivation of flippases in Candida parapsilosis

2021 ◽  
Author(s):  
Sean Bergin ◽  
Fang Zhao ◽  
Adam P Ryan ◽  
Carolin A Müller ◽  
Conrad A Nieduszynski ◽  
...  
Keyword(s):  
Plasma Membrane ◽  
Copy Number ◽  
Candida Parapsilosis ◽  
Copy Number Variations ◽  
Loss Of Function ◽  
Adaptive Laboratory Evolution ◽  
Pathogenic Yeast ◽  
Lipid Asymmetry ◽  
Evolution Experiment ◽  
Almost All

Flippases and floppases are two classes of proteins that have opposing functions in the maintenance of lipid asymmetry of the plasma membrane. Flippases translocate lipids from the exoplasmic leaflet to the cytosolic leaflet, and floppases act in the opposite direction. Phosphatidylcholine (PC) is a major component of the eukaryotic plasma membrane and is asymmetrically distributed, being more abundant in the exoplasmic leaflet. Here we show that gene amplification of a putative PC floppase or double disruption of two PC flippases in the pathogenic yeast Candida parapsilosis results in resistance to miltefosine, an alkylphosphocholine drug that affects PC metabolism that has recently been granted orphan drug designation approval by the US FDA for treatment of invasive candidiasis. We analysed the genomes of 170 C. parapsilosis isolates and found that 107 of them have copy number variations (CNVs) at the RTA3 gene. RTA3 encodes a putative PC floppase whose deletion is known to increase the inward translocation of PC in Candida albicans. RTA3 copy number ranges from 2 to >40 across the C. parapsilosis isolates. Interestingly, 16 distinct CNVs with unique endpoints were identified, and phylogenetic analysis shows that almost all of them have originated only once. We found that increased copy number of RTA3 correlates with miltefosine resistance. Additionally, we conducted an adaptive laboratory evolution experiment in which two C. parapsilosis isolates were cultured in increasing concentrations of miltefosine over 26 days. Two genes, CPAR2_303950 and CPAR2_102700, gained homozygous protein-disrupting mutations in the evolved strains and code for putative PC flippases homologous to S. cerevisiae DNF1. Our results indicate that alteration of lipid asymmetry across the plasma membrane is a key mechanism of miltefosine resistance. We also find that C. parapsilosis is likely to gain resistance to miltefosine rapidly, because many isolates carry loss-of-function alleles in one of the flippase genes.

scholarly journals Electron donor cytochrome b5 is required for hyphal tip accumulation of sterol-rich plasma membrane domains and membrane fluidity in Aspergillus fumigatus

2020 ◽  
Author(s):  
Chi Zhang ◽  
Yiran Ren ◽  
Lu Gao ◽  
Huiyu Gu ◽  
Ling Lu
Keyword(s):  
Plasma Membrane ◽  
Aspergillus Fumigatus ◽  
Membrane Fluidity ◽  
Electron Donor ◽  
Cytochrome B5 ◽  
Normal Growth ◽  
Ergosterol Biosynthesis ◽  
Membrane Domains ◽  
Growth Defects ◽  
C Terminus

The electron donor cytochrome b5 (CybE/Cyb5) fuels the activity of the ergosterol biosynthesis-related P450 enzymes/P450s by providing electrons to P450s to promote ergosterol biosynthesis. Previous studies reported that lack of Aspergillus fumigatus (A. fumigatus) CybE reduces the proportion of ergosterol in total sterols and induces severe growth defects. However, the molecular characteristics of CybE and the underlying mechanism for CybE maintaining A. fumigatus growth remain poorly understood. Here, we found that CybE locates at the endoplasmic reticulum by its C-terminus with two transmembrane regions. Therefore, lack of the C-terminus of CybE is able to phenocopy a cybE deletion. Notably, cybE deletion reduced the accumulation of the sterol-rich plasma membrane domains (SRDs, the assembly platform of polarity factors/cell end markers and growth machinery) in hyphal tips and decreased membrane fluidity, which correspond to tardiness of hyphal extension and hypersensitivity to low temperature in cybE deletion mutant. Additionally, overexpressing another electron donor-heme-independent P450 reductase (CPR) significantly rescued growth defects and recovered SRD accumulation in deletion of cybE almost to the wild-type level, suggesting CybE maintaining the growth and deposition of SRDs in hyphal tips attributes to its nature as an electron donor. Protein pull-down assays revealed that CybE probably participates in metabolism and transfer of lipids, construction of cytoskeleton and mitochondria-associated energy metabolism to maintain the SRD accumulation in hyphal tips, membrane fluidity and hyphal extension. Findings in this study give a hint that inhibition of CybE may be an effective strategy for resisting the infection of the human pathogen A. fumigatus. Importance Investigating the knowledge of the growth regulation in the human opportunistic pathogen A. fumigatus is conducive to design new antifungal approach. The electron donor cytochrome b5 (CybE) plays a crucial role in maintaining the normal growth of A. fumigatus, however, the potential mechanism remains elusive. Herein, we characterized the molecular features of CybE and found the C-terminus with two transmembrane domains are required for its ER localization and functions. In addition, we demonstrated that CprA, an electron donor-heme-independent P450 reductase, provides a reciprocal function for the missing cytochrome b5 protein-CybE in A. fumigatus. CybE maintains the normal growth probably via supporting two crucial physiological processes, the SRD accumulation in hyphal tips and membrane fluidity. Therefore, our finding reveals the mechanisms underlying the regulatory effect of CybE on A. fumigatus growth and indicates that inhibition of CybE might be an effective approach for alleviating A. fumigatus infection.

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