title: AtRAB-H1b and AtRAB-H1c GTPases, homologues of the yeast Ypt6, target reporter proteins to the Golgi when expressed in Nicotiana tabacum and Arabidopsis thaliana.
abstract: Ypt/Rab GTPases act as key regulators of intracellular traffic through the conformational differences exhibited by their GTP or GDP-bound forms. In this paper, two Arabidopsis Ypt6 homologues, AtRAB-H1(b) and AtRAB-H1(c) were characterized and compared. Using a live cell imaging approach, it is shown that yellow fluorescent protein-fusions (YFP) of AtRAB-H1(b) and AtRAB-H1(c) locate to the Golgi and to the cytosol in both Nicotiana tabacum and in Arabidopsis thaliana. In addition, YFP-AtRAB-H1(b) targets an as yet unknown compartment not labelled by YFP-AtRAB-H1(c) or Golgi markers. It is also shown that the subcellular location of YFP-AtRAB-H1(b) and YFP-AtRAB-H1(c) is affected by the state of GTP-binding and that expression of a GTP-deficient mutant results in increased apoplastic fluorescence of a secretory form of YFP.
authors.affiliation: School of Life Sciences, Oxford Brookes University, Gipsy Lane, Oxford OX3 0BP, UK.
authors.forename: Jorunn Nergaard
authors.initials: JN
authors.lastname: Johansen
authors.forename: Cheung-Ming
authors.initials: CM
authors.lastname: Chow
authors.forename: Ian
authors.initials: I
authors.lastname: Moore
authors.forename: Chris
authors.initials: C
authors.lastname: Hawes
mesh_terms: D017360:Arabidopsis / Q000235:genetics* / Q000378:metabolism; D029681:Arabidopsis Proteins / Q000235:genetics / Q000378:metabolism*; D003600:Cytosol / Q000378:metabolism; D015870:Gene Expression; D017930:Genes, Reporter; D006056:Golgi Apparatus / Q000235:genetics / Q000378:metabolism*; D006160:Guanosine Triphosphate / Q000378:metabolism; D011485:Protein Binding; D021381:Protein Transport; D011993:Recombinant Fusion Proteins / Q000235:genetics / Q000378:metabolism; D014026:Nicotiana / Q000235:genetics* / Q000378:metabolism; D020691:rab GTP-Binding Proteins / Q000235:genetics / Q000378:metabolism*
chemical_list: D029681:Arabidopsis Proteins; D011993:Recombinant Fusion Proteins; D006160:Guanosine Triphosphate; C544322:Rab-H1b protein, Arabidopsis; C544321:Rab-H1c protein, Arabidopsis; D020691:rab GTP-Binding Proteins