A potential pathway for flippase-facilitated glucosylceramide catabolism in plants
- 2 October 2020
- journal article
- research article
- Published by Informa UK Limited in Plant Signaling & Behavior
- Vol. 15 (10)
- https://doi.org/10.1080/15592324.2020.1783486
Abstract
The Aminophospholipid ATPase (ALA) family of plant lipid flippases is involved in the selective transport of lipids across membrane bilayers. Recently, we demonstrated that double mutants lacking both ALA4 and -5 are severely dwarfed. Dwarfism inala4/5mutants was accompanied by cellular elongation defects and various lipidomic perturbations, including a 1.4-fold increase in the accumulation of glucosylceramides (GlcCers) relative to total sphingolipid content. Here, we present a potential model for flippase-facilitated GlcCer catabolism in plants, where a combination of ALA flippases transport GlcCers to cytosolic membrane surfaces where they are degraded by Glucosylceramidases (GCDs). GCDs remove the glucose headgroup from GlcCers to produce a ceramide (Cer) backbone, which can be further degraded tosphingoid bases (Sphs, e.g, phytosphingosine) and fatty acids (FAs). In the absence of GlcCer-transporting flippases, GlcCers are proposed to accumulate on extracytoplasmic (i.e., apoplastic) or lumenal membrane surfaces. As GlcCers are potential precursors for Sph production, impaired GlcCer catabolism might also result in the decreased production of the secondary messenger Sph-1-phosphate (Sph-1-P, e.g., phytosphingosine-1-P), a regulator of cell turgor. Importantly, we postulate that either GlcCer accumulation or reduced Sph-1-P signaling might contribute to the growth reductions observed inala4/5mutants. Similar catabolic pathways have been proposed for humans and yeast, suggesting flippase-facilitated GlcCer catabolism is conserved across eukaryotes.Keywords
This publication has 55 references indexed in Scilit:
- The Lipid Flippases ALA4 and ALA5 Play Critical Roles in Cell Expansion and Plant Growth1[OPEN]Plant Physiology, 2020
- Evolution and a revised nomenclature of P4 ATPases, a eukaryotic family of lipid flippasesBiochimica et Biophysica Acta (BBA) - Biomembranes, 2019
- Phospholipid flipping involves a central cavity in P4 ATPasesScientific Reports, 2017
- Identification of a Sphingolipid α-Glucuronosyltransferase That Is Essential for Pollen Function inArabidopsisPlant Cell, 2014
- Arabidopsis mutants of sphingolipid fatty acid α‐hydroxylases accumulate ceramides and salicylatesNew Phytologist, 2012
- A Putative Plant Aminophospholipid Flippase, the Arabidopsis P4 ATPase ALA1, Localizes to the Plasma Membrane following Association with a β-SubunitPLOS ONE, 2012
- Sphingolipids Containing Very-Long-Chain Fatty Acids Define a Secretory Pathway for Specific Polar Plasma Membrane Protein Targeting inArabidopsisPlant Cell, 2011
- An Inositolphosphorylceramide Synthase Is Involved in Regulation of Plant Programmed Cell Death Associated with Defense inArabidopsisPlant Cell, 2008
- Sphingolipid Long-Chain Base Hydroxylation Is Important for Growth and Regulation of Sphingolipid Content and Composition inArabidopsisPlant Cell, 2008
- The Arabidopsis P4-ATPase ALA3 Localizes to the Golgi and Requires a β-Subunit to Function in Lipid Translocation and Secretory Vesicle FormationPlant Cell, 2008