title: A specific role for Arabidopsis TRAPPII in post-Golgi trafficking that is crucial for cytokinesis and cell polarity.
abstract: Cytokinesis and cell polarity are supported by membrane trafficking from the trans-Golgi network (TGN), but the molecular mechanisms that promote membrane trafficking from the TGN are poorly defined in plant cells. Here we show that TRAPPII in Arabidopsis regulates the post-Golgi trafficking that is crucial for assembly of the cell plate and cell polarity. Disruptions of AtTRS120 or AtTRS130, two genes encoding two key subunits of TRAPPII, result in defective cytokinesis and cell polarity in embryogenesis and seedling development. In attrs120 and attrs130, the organization and trafficking in the endoplasmic reticulum (ER)-Golgi interface are normal. However, post-Golgi trafficking to the cell plate and to the cell wall, but not to the vacuole, is impaired. Furthermore, TRAPPII is required for the selective transport of PIN2, but not PIN1, to the plasma membrane. We revealed that AtTRS130 is co-localized with RAB-A1c. Expression of constitutively active RAB-A1c partially rescues attrs130. RAB-A1c, which resides at the TGN, is delocalized to the cytosol in attrs130. We propose that TRAPPII in Arabidopsis acts upstream of Rab-A GTPases in post-Golgi membrane trafficking in plant cells.
authors.affiliation: Developmental Biology Research Initiatives, Department of Biology, McGill University, 1205 Dr Penfield Avenue, Montreal, Quebec H3A 1B1, Canada.
authors.forename: Xingyun
authors.initials: X
authors.lastname: Qi
authors.forename: Minako
authors.initials: M
authors.lastname: Kaneda
authors.forename: Jun
authors.initials: J
authors.lastname: Chen
authors.forename: Anja
authors.initials: A
authors.lastname: Geitmann
authors.forename: Huanquan
authors.initials: H
authors.lastname: Zheng
mesh_terms: D017360:Arabidopsis / Q000196:embryology / Q000235:genetics / Q000502:physiology* / Q000648:ultrastructure; D029681:Arabidopsis Proteins / Q000235:genetics / Q000378:metabolism*; D018797:Cell Cycle Proteins / Q000235:genetics / Q000378:metabolism; D002462:Cell Membrane / Q000378:metabolism; D016764:Cell Polarity / Q000502:physiology*; D002473:Cell Wall / Q000378:metabolism; D048749:Cytokinesis / Q000502:physiology*; D003600:Cytosol / Q000378:metabolism; D004721:Endoplasmic Reticulum / Q000378:metabolism; D020558:GTP Phosphohydrolases / Q000235:genetics / Q000378:metabolism; D049452:Green Fluorescent Proteins; D008938:Mitosis; D016254:Mutagenesis, Insertional; D010641:Phenotype; D021381:Protein Transport / Q000502:physiology; D036226:Seedlings / Q000196:embryology / Q000235:genetics / Q000502:physiology / Q000648:ultrastructure; D014617:Vacuoles / Q000378:metabolism; D020691:rab GTP-Binding Proteins / Q000235:genetics / Q000378:metabolism; D021601:trans-Golgi Network / Q000378:metabolism*
chemical_list: D029681:Arabidopsis Proteins; D018797:Cell Cycle Proteins; D020558:GTP Phosphohydrolases; D049452:Green Fluorescent Proteins; D020691:rab GTP-Binding Proteins; C117013:AT5G57090 protein, Arabidopsis; C586781:TRS120 protein, Arabidopsis; C586782:TRS130 protein, Arabidopsis; C586780:RABA1c protein, Arabidopsis