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Forschungsdatenbank PMU-SQQUID

pH modulates interaction of 14-3-3 proteins with pollen plasma membrane H+ ATPases independently from phosphorylation.
Pertl-Obermeyer, H; Gimeno, A; Kuchler, V; Servili, E; Huang, S; Fang, H; Lang, V; Sydow, K; Pockl, M; Schulze, WX; Obermeyer, G
J EXP BOT. 2022; 73(1): 168-181.
Originalarbeiten (Zeitschrift)

PMU-Autor/inn/en

Fang Han

Abstract

Pollen grains transport the sperm cells through the style tissue via a fast-growing pollen tube to the ovaries where fertilization takes place. Pollen tube growth requires a precisely regulated network of cellular as well as molecular events including the activity of the plasma membrane H+ ATPase, which is known to be regulated by reversible protein phosphorylation and subsequent binding of 14-3-3 isoforms. Immunodetection of the phosphorylated penultimate threonine residue of the pollen plasma membrane H+ ATPase (LilHA1) of Lilium longiflorum pollen revealed a sudden increase in phosphorylation with the start of pollen tube growth. In addition to phosphorylation, pH modulated the binding of 14-3-3 isoforms to the regulatory domain of the H+ ATPase, whereas metabolic components had only small effects on 14-3-3 binding, as tested with in vitro assays using recombinant 14-3-3 isoforms and phosphomimicking substitutions of the threonine residue. Consequently, local H+ influxes and effluxes as well as pH gradients in the pollen tube tip are generated by localized regulation of the H+ ATPase activity rather than by heterogeneous localized distribution in the plasma membrane.


Useful keywords (using NLM MeSH Indexing)

14-3-3 Proteins*/metabolism

Cell Membrane/metabolism

Hydrogen-Ion Concentration

Phosphorylation

Plant Proteins/genetics

Plant Proteins/metabolism

Pollen/metabolism

Pollen Tube/metabolism

Proton-Translocating ATPases*/metabolism


Find related publications in this database (Keywords)

14-3-3 protein
cytosolic pH
phosphorylation
plasma membrane H+-ATPase
pollen
protein-protein interaction
tip growth