scholarly journals ER-Localized PIN Carriers: Regulators of Intracellular Auxin Homeostasis

Plants ◽  
2020 ◽  
Vol 9 (11) ◽  
pp. 1527
Author(s):  
Nayyer Abdollahi Sisi ◽  
Kamil Růžička
Keyword(s):  
Endoplasmic Reticulum ◽  
Plasma Membrane ◽  
Subcellular Localization ◽  
Plant Development ◽  
Current Knowledge ◽  
Structural Features ◽  
Structure Evolution ◽  
Auxin Homeostasis ◽  
Auxin Efflux Carriers ◽  
Hydrophilic Loop

The proper distribution of the hormone auxin is essential for plant development. It is channeled by auxin efflux carriers of the PIN family, typically asymmetrically located on the plasma membrane (PM). Several studies demonstrated that some PIN transporters are also located at the endoplasmic reticulum (ER). From the PM-PINs, they differ in a shorter internal hydrophilic loop, which carries the most important structural features required for their subcellular localization, but their biological role is otherwise relatively poorly known. We discuss how ER-PINs take part in maintaining intracellular auxin homeostasis, possibly by modulating the internal levels of IAA; it seems that the exact identity of the metabolites downstream of ER-PINs is not entirely clear as well. We further review the current knowledge about their predicted structure, evolution and localization. Finally, we also summarize their role in plant development.

scholarly journals The PIN-FORMED Auxin Efflux Carriers in Plants

2018 ◽  
Vol 19 (9) ◽  
pp. 2759 ◽  
Author(s):  
Jing-Jing Zhou ◽  
Jie Luo
Keyword(s):  
Subcellular Location ◽  
Structure Evolution ◽  
Dependent Manner ◽  
Subcellular Trafficking ◽  
Developmental Processes ◽  
Auxin Distribution ◽  
Development Processes ◽  
Auxin Efflux Carriers ◽  
Hydrophilic Loop ◽  
Polar Distribution

Auxin plays crucial roles in multiple developmental processes, such as embryogenesis, organogenesis, cell determination and division, as well as tropic responses. These processes are finely coordinated by the auxin, which requires the polar distribution of auxin within tissues and cells. The intercellular directionality of auxin flow is closely related to the asymmetric subcellular location of PIN-FORMED (PIN) auxin efflux transporters. All PIN proteins have a conserved structure with a central hydrophilic loop domain, which harbors several phosphosites targeted by a set of protein kinases. The activities of PIN proteins are finely regulated by diverse endogenous and exogenous stimuli at multiple layers—including transcriptional and epigenetic levels, post-transcriptional modifications, subcellular trafficking, as well as PINs’ recycling and turnover—to facilitate the developmental processes in an auxin gradient-dependent manner. Here, the recent advances in the structure, evolution, regulation and functions of PIN proteins in plants will be discussed. The information provided by this review will shed new light on the asymmetric auxin-distribution-dependent development processes mediated by PIN transporters in plants.

PIN6 auxin transporter at endoplasmic reticulum and plasma membrane mediates auxin homeostasis and organogenesis in Arabidopsis

2016 ◽  
Vol 211 (1) ◽  
pp. 65-74 ◽  
Author(s):  
Sibu Simon ◽  
Petr Skůpa ◽  
Tom Viaene ◽  
Marta Zwiewka ◽  
Ricardo Tejos ◽  
...  
Keyword(s):  
Endoplasmic Reticulum ◽  
Plasma Membrane ◽  
Auxin Homeostasis ◽  
Auxin Transporter

scholarly journals Subcellular localization of the enzyme that forms mannosyl retinyl phosphate from guanosine diphosphate [14C]mannose and retinyl phosphate

1979 ◽  
Vol 180 (3) ◽  
pp. 449-453 ◽  
Author(s):  
M J Smith ◽  
J B Schreiber ◽  
G Wolf
Keyword(s):  
Endoplasmic Reticulum ◽  
Plasma Membrane ◽  
Golgi Apparatus ◽  
Subcellular Localization ◽  
Rat Liver ◽  
Rough Endoplasmic Reticulum ◽  
Subcellular Distribution ◽  
Smooth Endoplasmic Reticulum ◽  
Marker Enzymes ◽  
Guanosine Diphosphate

The subcellular distribution of the enzyme catalysing the conversion of retinyl phosphate and GDP-[14C]mannose into [14C]mannosyl retinyl phosphate was determined by using subcellular fractions of rat liver. Purity of fractions, as determined by marker enzymes, was 80% or better. The amount of mannosyl retinyl phosphate formed (pmol/min per mg of protein) for each fraction was: rough endoplasmic reticulum 0.48 +/- 0.09 (mean +/- S.D.); smooth membranes (consisting of 60% smooth endoplasmic reticulum and 40% Golgi apparatus), 0.18 +/- 0.03; Golgi apparatus, 0.13 +/- 0.03; and plasma membrane 0.02.

The subcellular localization of testicular sulfogalactoglycerolipid

1980 ◽  
Vol 58 (3) ◽  
pp. 225-229 ◽  
Author(s):  
Abbey Klugerman ◽  
Mary Judith Kornblatt
Keyword(s):  
Alkaline Phosphatase ◽  
Endoplasmic Reticulum ◽  
Plasma Membrane ◽  
Golgi Apparatus ◽  
Subcellular Localization ◽  
Density Distribution ◽  
Equilibrium Density ◽  
Enzyme Markers ◽  
Germinal Cells

The subcellular localization of sulfogalactoglycerolipid in rat testicular germinal cells was determined. The sulfolipid of young rats was labelled in vivo with Na235SO4. Rat testis cell suspensions were prepared, homogenized, and centrifuged on linear, continuous, sucrose gradients. The labelled lipid had the identical equilibrium density distribution pattern as alkaline phosphatase, an enzyme of the plasma membrane. The pattern of the sulfolipid was different from the patterns of enzyme markers for the Golgi apparatus, lysosomes, mitochondria, and endoplasmic reticulum. From these results, we conclude that sulfogalactoglycerolipid is located on the plasma membrane of rat testicular germinal cells.

Triple Fixation For Electron Microscopy

1968 ◽  
Vol 26 ◽  
pp. 90-91 ◽  
Author(s):  
M. A. Hayat
Keyword(s):  
Electron Microscopy ◽  
Endoplasmic Reticulum ◽  
Electron Beam ◽  
Plasma Membrane ◽  
Myelin Sheath ◽  
Good Deal ◽  
Granular Structure ◽  
Oxidizing Agent ◽  
Fixation Technique ◽  
Large Clusters

Potassium permanganate has been successfully employed to study membranous structures such as endoplasmic reticulum, Golgi, plastids, plasma membrane and myelin sheath. Since KMnO4 is a strong oxidizing agent, deposition of manganese or its oxides account for some of the observed contrast in the lipoprotein membranes, but a good deal of it is due to the removal of background proteins either by dehydration agents or by volatalization under the electron beam. Tissues fixed with KMnO4 exhibit somewhat granular structure because of the deposition of large clusters of stain molecules. The gross arrangement of membranes can also be modified. Since the aim of a good fixation technique is to preserve satisfactorily the cell as a whole and not the best preservation of only a small part of it, a combination of a mixture of glutaraldehyde and acrolein to obtain general preservation and KMnO4 to enhance contrast was employed to fix plant embryos, green algae and fungi.

scholarly journals Synaptotagmins at the endoplasmic reticulum–plasma membrane contact sites maintain diacylglycerol homeostasis during abiotic stress

2021 ◽  
Author(s):  
Noemi Ruiz-Lopez ◽  
Jessica Pérez-Sancho ◽  
Alicia Esteban del Valle ◽  
Richard P Haslam ◽  
Steffen Vanneste ◽  
...  
Keyword(s):  
Endoplasmic Reticulum ◽  
Plasma Membrane ◽  
Abiotic Stress ◽  
Fluorescent Protein ◽  
Mechanical Damage ◽  
Membrane Contact Sites ◽  
Contact Sites ◽  
Membrane Contact ◽  
Green Fluorescent

Abstract Endoplasmic reticulum-plasma membrane contact sites (ER-PM CS) play fundamental roles in all eukaryotic cells. Arabidopsis thaliana mutants lacking the ER-PM protein tether synaptotagmin1 (SYT1) exhibit decreased plasma membrane (PM) integrity under multiple abiotic stresses such as freezing, high salt, osmotic stress and mechanical damage. Here, we show that, together with SYT1, the stress-induced SYT3 is an ER-PM tether that also functions in maintaining PM integrity. The ER-PM CS localization of SYT1 and SYT3 is dependent on PM phosphatidylinositol-4-phosphate and is regulated by abiotic stress. Lipidomic analysis revealed that cold stress increased the accumulation of diacylglycerol at the PM in a syt1/3 double mutant relative to wild type while the levels of most glycerolipid species remain unchanged. Additionally, the SYT1-green fluorescent protein (GFP) fusion preferentially binds diacylglycerol in vivo with little affinity for polar glycerolipids. Our work uncovers a SYT-dependent mechanism of stress adaptation counteracting the detrimental accumulation of diacylglycerol at the PM produced during episodes of abiotic stress.

scholarly journals Recent Development on Plant Aldehyde Dehydrogenase Enzymes and Their Functions in Plant Development and Stress Signaling

Genes ◽  
2020 ◽  
Vol 12 (1) ◽  
pp. 51
Author(s):  
Adesola J. Tola ◽  
Amal Jaballi ◽  
Hugo Germain ◽  
Tagnon D. Missihoun
Keyword(s):  
Plant Development ◽  
Critical Analysis ◽  
Current Knowledge ◽  
Stress Signaling ◽  
Oxygen Species ◽  
Abiotic And Biotic Stresses ◽  
Aldehyde Dehydrogenases ◽  
Biotic Stresses ◽  
Wide Range ◽  
Excessive Accumulation

Abiotic and biotic stresses induce the formation of reactive oxygen species (ROS), which subsequently causes the excessive accumulation of aldehydes in cells. Stress-derived aldehydes are commonly designated as reactive electrophile species (RES) as a result of the presence of an electrophilic α, β-unsaturated carbonyl group. Aldehyde dehydrogenases (ALDHs) are NAD(P)+-dependent enzymes that metabolize a wide range of endogenous and exogenous aliphatic and aromatic aldehyde molecules by oxidizing them to their corresponding carboxylic acids. The ALDH enzymes are found in nearly all organisms, and plants contain fourteen ALDH protein families. In this review, we performed a critical analysis of the research reports over the last decade on plant ALDHs. Newly discovered roles for these enzymes in metabolism, signaling and development have been highlighted and discussed. We concluded with suggestions for future investigations to exploit the potential of these enzymes in biotechnology and to improve our current knowledge about these enzymes in gene signaling and plant development.

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