Oligomeric Dop1p is part of the endosomal Neo1p-Ysl2p-Arl1p membrane remodeling complex.
Yeast Dop1p is an essential protein that is highly conserved in evolution and whose function is largely unknown. Here, we provide evidence that Dop1p localizes to endosomes and exists in a complex with two other conserved proteins: Neo1p, a P(4)-ATPase and putative flippase, and the scaffolding protein Ysl2p/Mon2p. The latter operates during membrane budding at the tubular endosomal network/trans-Golgi network (TEN/TGN) in a process that includes clathrin recruitment via adaptor proteins. Consistent with a role for Dop1p during this process, temperature-sensitive dop1-3 cells accumulate multivesicular, elongated tubular and ring-like structures similar to those displayed by neo1 and ysl2 mutants. In further agreement with the concept of Dop1p-Neo1p-Ysl2p complex formation and co-operation, we show that dop1-3 cells exhibit reduced levels of Neo1p and Ysl2p at steady state. Conversely, mutations or deletions in NEO1 and YSL2 lead to a decrease in Dop1p levels. In addition to binding to Neo1p and Ysl2p, Dop1p can form dimers or multimers. A critical region for dimerization resides in the C-terminus with leucine zipper-like domains. Dop1p's membrane association is largely mediated by its internal region, but Ysl2p might not be crucial for membrane recruitment.
Barbosa
Sónia
S
University of Stuttgart, Institute for Biochemistry, D-70569 Stuttgart, Germany.
Pratte
Dagmar
D
Schwarz
Heinz
H
Pipkorn
Rüdiger
R
Singer-Krüger
Birgit
B
D000251:Adenosine Triphosphatases / Q000235:genetics / Q000378:metabolism*; D002462:Cell Membrane / Q000737:chemistry / Q000378:metabolism; D011992:Endosomes / Q000737:chemistry / Q000378:metabolism*; D015966:Gene Expression Regulation, Fungal; D007425:Intracellular Membranes / Q000378:metabolism*; D026901:Membrane Transport Proteins / Q000235:genetics / Q000378:metabolism*; D020559:Monomeric GTP-Binding Proteins / Q000235:genetics / Q000378:metabolism*; D046912:Multiprotein Complexes / Q000737:chemistry / Q000378:metabolism; D009154:Mutation; D049294:Phospholipid Transfer Proteins; D011993:Recombinant Fusion Proteins / Q000235:genetics / Q000378:metabolism; D012441:Saccharomyces cerevisiae / Q000166:cytology / Q000235:genetics / Q000378:metabolism; D029701:Saccharomyces cerevisiae Proteins / Q000235:genetics / Q000378:metabolism*; D033921:Vesicular Transport Proteins / Q000235:genetics / Q000378:metabolism*; D021601:trans-Golgi Network / Q000378:metabolism
C427246:CDC50 protein, S cerevisiae; C508366:Dop1 protein, S cerevisiae; C507257:MON2 protein, S cerevisiae; D026901:Membrane Transport Proteins; D046912:Multiprotein Complexes; D049294:Phospholipid Transfer Proteins; D011993:Recombinant Fusion Proteins; D029701:Saccharomyces cerevisiae Proteins; D033921:Vesicular Transport Proteins; C487039:ARL1 protein, S cerevisiae; D000251:Adenosine Triphosphatases; D020559:Monomeric GTP-Binding Proteins; C104013:NEO1 protein, S cerevisiae