Localization and domain characterization of Arabidopsis golgin candidates.
Golgins are large coiled-coil proteins that play a role in tethering of vesicles to Golgi membranes and in maintaining the overall structure of the Golgi apparatus. Six Arabidopsis proteins with the structural characteristics of golgins were isolated and shown to locate to Golgi stacks when fused to GFP. Two of these golgin candidates (GC1 and GC2) possess C-terminal transmembrane (TM) domains with similarity to the TM domain of human golgin-84. The C-termini of two others (GC3/GDAP1 and GC4) contain conserved GRAB and GA1 domains that are also found in yeast Rud3p and human GMAP210. GC5 shares similarity with yeast Sgm1p and human TMF and GC6 with yeast Uso1p and human p115. When fused to GFP, the C-terminal domains of AtCASP and GC1 to GC6 localized to the Golgi, showing that they contain Golgi localization motifs. The N-termini, on the other hand, label the cytosol or nucleus. Immuno-gold labelling and co-expression with the cis Golgi Q-SNARE Memb11 resulted in a more detailed picture of the sub-Golgi location of some of these putative golgins. Using two independent assays it is further demonstrated that the interaction between GC5, the TMF homologue, and the Rab6 homologues is conserved in plants.
Latijnhouwers
Maita
M
Plant Pathology Programme, Scottish Crop Research Institute, Invergowrie, Dundee DD2 5DA, UK.
Gillespie
Trudi
T
Boevink
Petra
P
Kriechbaumer
Verena
V
Hawes
Chris
C
Carvalho
Claudine M
CM
D000595:Amino Acid Sequence; D000818:Animals; D017360:Arabidopsis / Q000378:metabolism*; D029681:Arabidopsis Proteins / Q000378:metabolism*; D006056:Golgi Apparatus / Q000378:metabolism*; D000077614:Golgi Matrix Proteins; D049452:Green Fluorescent Proteins / Q000378:metabolism; D007150:Immunohistochemistry; D008565:Membrane Proteins / Q000378:metabolism*; D008969:Molecular Sequence Data; D017434:Protein Structure, Tertiary; D017386:Sequence Homology, Amino Acid; D020798:Two-Hybrid System Techniques; D020691:rab GTP-Binding Proteins / Q000378:metabolism
D029681:Arabidopsis Proteins; C504617:CASP protein, Arabidopsis; C496228:GRIP protein, Arabidopsis; D000077614:Golgi Matrix Proteins; D008565:Membrane Proteins; C094135:Rab6 protein; D049452:Green Fluorescent Proteins; D020691:rab GTP-Binding Proteins