title: Retromer subunits VPS35A and VPS29 mediate prevacuolar compartment (PVC) function in Arabidopsis.
abstract: Intracellular protein routing is mediated by vesicular transport which is tightly regulated in eukaryotes. The protein and lipid homeostasis depends on coordinated delivery of de novo synthesized or recycled cargoes to the plasma membrane by exocytosis and their subsequent removal by rerouting them for recycling or degradation. Here, we report the characterization of protein affected trafficking 3 (pat3) mutant that we identified by an epifluorescence-based forward genetic screen for mutants defective in subcellular distribution of Arabidopsis auxin transporter PIN1-GFP. While pat3 displays largely normal plant morphology and development in nutrient-rich conditions, it shows strong ectopic intracellular accumulations of different plasma membrane cargoes in structures that resemble prevacuolar compartments (PVC) with an aberrant morphology. Genetic mapping revealed that pat3 is defective in vacuolar protein sorting 35A (VPS35A), a putative subunit of the retromer complex that mediates retrograde trafficking between the PVC and trans-Golgi network. Similarly, a mutant defective in another retromer subunit, vps29, shows comparable subcellular defects in PVC morphology and protein accumulation. Thus, our data provide evidence that the retromer components VPS35A and VPS29 are essential for normal PVC morphology and normal trafficking of plasma membrane proteins in plants. In addition, we show that, out of the three VPS35 retromer subunits present in Arabidopsis thaliana genome, the VPS35 homolog A plays a prevailing role in trafficking to the lytic vacuole, presenting another level of complexity in the retromer-dependent vacuolar sorting.
authors.affiliation: Mendel Centre for Plant Genomics and Proteomics, Central European Institute of Technology (CEITEC), Masaryk University (MU), Kamenice 5, CZ-625 00, Brno, Czech Republic.
authors.forename: Tomasz
authors.initials: T
authors.lastname: Nodzynski
authors.forename: Mugurel I
authors.initials: MI
authors.lastname: Feraru
authors.forename: Sibylle
authors.initials: S
authors.lastname: Hirsch
authors.forename: Riet
authors.initials: R
authors.lastname: De Rycke
authors.forename: Claudiu
authors.initials: C
authors.lastname: Niculaes
authors.forename: Wout
authors.initials: W
authors.lastname: Boerjan
authors.forename: Jelle
authors.initials: J
authors.lastname: Van Leene
authors.forename: Geert
authors.initials: G
authors.lastname: De Jaeger
authors.forename: Steffen
authors.initials: S
authors.lastname: Vanneste
authors.forename: Jirí
authors.initials: J
authors.lastname: Friml
mesh_terms: D017360:Arabidopsis / Q000235:genetics / Q000502:physiology*; D029681:Arabidopsis Proteins / Q000378:metabolism / Q000502:physiology*; D002451:Cell Compartmentation; D004705:Endocytosis; D049452:Green Fluorescent Proteins / Q000235:genetics / Q000378:metabolism; D008565:Membrane Proteins / Q000378:metabolism / Q000502:physiology; D008969:Molecular Sequence Data; D009154:Mutation; D021381:Protein Transport; D014617:Vacuoles / Q000378:metabolism*; D033921:Vesicular Transport Proteins / Q000378:metabolism / Q000502:physiology*
chemical_list: D029681:Arabidopsis Proteins; C515611:Mag1 protein, Arabidopsis; D008565:Membrane Proteins; C581314:VPS35 protein, Arabidopsis; D033921:Vesicular Transport Proteins; D049452:Green Fluorescent Proteins
keywords: Arabidopsis thaliana.; VPS29; VPS35; prevacuolar compartment (PVC); retromer; vacuolar trafficking