Vacuolin, a flotillin/reggie-related protein from Dictyostelium oligomerizes for endosome association.
We have analysed the domain structure of vacuolin, a Dictyostelium protein binding to the cytoplasmic surface of late endosomes. Localisation studies using GFP fusions together with a yeast two-hybrid analysis and co-immunoprecipitation experiments reveal that a region close to the C-terminus mediates oligomer formation of the protein through a coiled-coil mechanism which in turn is a prerequisite for the efficient binding to endosomal membranes via a prohibitin (PHB) domain in the middle of the molecule. Overexpression of the coiled-coil domain strongly competes with endogenous vacuolin in the oligomers and reduces the efficiency of membrane targeting. The domain arrangement of vacuolin is most similar to flotillin/reggie, a protein found on late endosomes of mammalian cells.
Wienke
Dirk
D
Laboratory for Molecular Cell Biology, University College London, London, UK.
Drengk
Anja
A
Schmauch
Christian
C
Jenne
Nicole
N
Maniak
Markus
M
D000595:Amino Acid Sequence; D000818:Animals; D003598:Cytoskeletal Proteins / Q000235:genetics / Q000378:metabolism*; D004023:Dictyostelium / Q000166:cytology / Q000378:metabolism*; D011992:Endosomes / Q000378:metabolism*; D007425:Intracellular Membranes / Q000378:metabolism; D008969:Molecular Sequence Data; D017434:Protein Structure, Tertiary; D015800:Protozoan Proteins / Q000235:genetics / Q000378:metabolism*; D011993:Recombinant Fusion Proteins / Q000235:genetics / Q000378:metabolism; D016415:Sequence Alignment; D020798:Two-Hybrid System Techniques
D003598:Cytoskeletal Proteins; D015800:Protozoan Proteins; D011993:Recombinant Fusion Proteins; C105803:vac A protein, Dictyostelium discoideum