title: Conserved Arabidopsis ECHIDNA protein mediates trans-Golgi-network trafficking and cell elongation.
abstract: Multiple steps of plant growth and development rely on rapid cell elongation during which secretory and endocytic trafficking via the trans-Golgi network (TGN) plays a central role. Here, we identify the ECHIDNA (ECH) protein from Arabidopsis thaliana as a TGN-localized component crucial for TGN function. ECH partially complements loss of budding yeast TVP23 function and a Populus ECH complements the Arabidopsis ech mutant, suggesting functional conservation of the genes. Compared with wild-type, the Arabidopsis ech mutant exhibits severely perturbed cell elongation as well as defects in TGN structure and function, manifested by the reduced association between Golgi bodies and TGN as well as mislocalization of several TGN-localized proteins including vacuolar H(+)-ATPase subunit a1 (VHA-a1). Strikingly, ech is defective in secretory trafficking, whereas endocytosis appears unaffected in the mutant. Some aspects of the ech mutant phenotype can be phenocopied by treatment with a specific inhibitor of vacuolar H(+)-ATPases, concanamycin A, indicating that mislocalization of VHA-a1 may account for part of the defects in ech. Hence, ECH is an evolutionarily conserved component of the TGN with a central role in TGN structure and function.
authors.affiliation: Umeå Plant Science Centre, Department of Forest Genetics and Plant Physiology, Swedish University of Agricultural Sciences, S-901 83 Umeå, Sweden.
authors.forename: Delphine
authors.initials: D
authors.lastname: Gendre
authors.forename: Jaesung
authors.initials: J
authors.lastname: Oh
authors.forename: Yohann
authors.initials: Y
authors.lastname: Boutté
authors.forename: Jacob G
authors.initials: JG
authors.lastname: Best
authors.forename: Lacey
authors.initials: L
authors.lastname: Samuels
authors.forename: Robert
authors.initials: R
authors.lastname: Nilsson
authors.forename: Tomohiro
authors.initials: T
authors.lastname: Uemura
authors.forename: Alan
authors.initials: A
authors.lastname: Marchant
authors.forename: Malcolm J
authors.initials: MJ
authors.lastname: Bennett
authors.forename: Markus
authors.initials: M
authors.lastname: Grebe
authors.forename: Rishikesh P
authors.initials: RP
authors.lastname: Bhalerao
mesh_terms: D000595:Amino Acid Sequence; D017360:Arabidopsis / Q000166:cytology / Q000235:genetics / Q000378:metabolism*; D029681:Arabidopsis Proteins / Q000235:genetics / Q000378:metabolism*; D001483:Base Sequence; D002451:Cell Compartmentation / Q000187:drug effects / Q000235:genetics / Q000502:physiology; D048430:Cell Shape / Q000235:genetics / Q000502:physiology; D018744:DNA, Plant / Q000235:genetics; D019143:Evolution, Molecular; D017343:Genes, Plant; D005816:Genetic Complementation Test; D018942:Macrolides / Q000494:pharmacology; D008969:Molecular Sequence Data; D009154:Mutation; D010641:Phenotype; D010802:Phylogeny; D030821:Plants, Genetically Modified; D012441:Saccharomyces cerevisiae / Q000235:genetics / Q000378:metabolism; D017386:Sequence Homology, Amino Acid; D033921:Vesicular Transport Proteins / Q000235:genetics / Q000378:metabolism*; D021601:trans-Golgi Network / Q000378:metabolism / Q000648:ultrastructure
chemical_list: D029681:Arabidopsis Proteins; D018744:DNA, Plant; C000592612:ECHIDNA protein, Arabidopsis; D018942:Macrolides; D033921:Vesicular Transport Proteins; C036978:concanamycin A