title: Characterization of the Arabidopsis thaliana exocyst complex gene families by phylogenetic, expression profiling, and subcellular localization studies.
abstract: *The exocyst is a complex of eight proteins (Sec3p, Sec5p, Sec6p, Sec8p, Sec10p, Sec15p, Exo70p and Exo84p) involved in tethering vesicles to the plasma membrane during regulated or polarized secretion. Here, the plant exocyst complex was explored in phylogenetic, expression, and subcellular localization studies. *Evolutionary relationships of predicted exocyst subunits were examined in the complete genomes of Arabidopsis thaliana, Oryza sativa, Populus trichocarpa and Physcomitrella patens. Furthermore, detailed expression profiling of the A. thaliana microarray databases was performed and subcellular localization patterns were studied. *Several plant exocyst subunit genes appear to have undergone gene expansion in a common ancestor and subsequent duplication events in independent plant lineages. Expression profiling revealed that the A. thaliana Exo70 gene family exhibits dynamic expression patterns, while the remaining exocyst subunit genes displayed more static profiles. Subcellular localization patterns for A. thaliana exocyst subunits ranged from cytosolic to endosomal compartments (with enrichment in the early endosomes and the trans-Golgi network). Interestingly, two endosomal-localized AtExo70 proteins also recruited other exocyst subunits to these compartments. *Overall subcellular localization patterns were observed that were also found in yeast and animal cells, and this, coupled with the evolutionary relationships, suggests that the exocyst may perform similar conserved functions in plants.
authors.affiliation: Department of Cell & Systems Biology and the Centre for the Analysis of Genome Evolution & Function, University of Toronto, Toronto, Ontario, Canada M5S 3B2.
authors.forename: Yolanda T
authors.initials: YT
authors.lastname: Chong
authors.forename: Satinder K
authors.initials: SK
authors.lastname: Gidda
authors.forename: Chris
authors.initials: C
authors.lastname: Sanford
authors.forename: John
authors.initials: J
authors.lastname: Parkinson
authors.forename: Robert T
authors.initials: RT
authors.lastname: Mullen
authors.forename: Daphne R
authors.initials: DR
authors.lastname: Goring
mesh_terms: D000818:Animals; D017360:Arabidopsis / Q000166:cytology / Q000235:genetics* / Q000378:metabolism; D029681:Arabidopsis Proteins / Q000235:genetics* / Q000378:metabolism; D005075:Biological Evolution; D019143:Evolution, Molecular; D005089:Exocytosis / Q000235:genetics*; D015870:Gene Expression; D020869:Gene Expression Profiling; D017343:Genes, Plant; D019684:Magnoliopsida / Q000235:genetics; D005810:Multigene Family; D010802:Phylogeny; D022161:Transport Vesicles / Q000235:genetics / Q000378:metabolism; D033921:Vesicular Transport Proteins / Q000235:genetics* / Q000378:metabolism
chemical_list: D029681:Arabidopsis Proteins; D033921:Vesicular Transport Proteins