Cdc50p Plays a Vital Role in the ATPase Reaction Cycle of the Putative Aminophospholipid Transporter Drs2p*♦
AUTOR(ES)
Lenoir, Guillaume
FONTE
American Society for Biochemistry and Molecular Biology
RESUMO
Members of the P4 subfamily of P-type ATPases are believed to catalyze transport of phospholipids across cellular bilayers. However, most P-type ATPases pump small cations or metal ions, and atomic structures revealed a transport mechanism that is conserved throughout the family. Hence, a challenging problem is to understand how this mechanism is adapted in P4-ATPases to flip phospholipids. P4-ATPases form heteromeric complexes with Cdc50 proteins. The primary role of these additional polypeptides is unknown. Here, we show that the affinity of yeast P4-ATPase Drs2p for its Cdc50-binding partner fluctuates during the transport cycle, with the strongest interaction occurring at a point where the enzyme is loaded with phospholipid ligand. We also find that specific interactions with Cdc50p are required to render the ATPase competent for phosphorylation at the catalytically important aspartate residue. Our data indicate that Cdc50 proteins are integral components of the P4-ATPase transport machinery. Thus, acquisition of these subunits may have been a crucial step in the evolution of flippases from a family of cation pumps.
ACESSO AO ARTIGO
http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=2709398Documentos Relacionados
- Flipping the P-type ATPase Script♦: Cdc50p Plays a Vital Role in the ATPase Reaction Cycle of the Putative Aminophospholipid Transporter Drs2p
- Cdc50p, a Protein Required for Polarized Growth, Associates with the Drs2p P-Type ATPase Implicated in Phospholipid Translocation in Saccharomyces cerevisiae
- Drs2p-coupled aminophospholipid translocase activity in yeast Golgi membranes and relationship to in vivo function
- Molecular Interactions of Yeast Neo1p, an Essential Member of the Drs2 Family of Aminophospholipid Translocases, and Its Role in Membrane Trafficking within the Endomembrane System
- An Arabidopsis cell cycle -dependent kinase-related gene, CDC2b, plays a role in regulating seedling growth in darkness.