Cdc50p plays a vital role in the ATPase reaction cycle of the putative aminophospholipid transporter Drs2p
| Autor: | Catheleyne F. Puts, Guillaume Lenoir, Patrick Williamson, Joost C. M. Holthuis |
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| Rok vydání: | 2009 |
| Předmět: |
Subfamily
Saccharomyces cerevisiae Proteins Protein subunit ATPase Saccharomyces cerevisiae Calcium-Transporting ATPases Biology In Vitro Techniques Transfection Biochemistry Catalysis chemistry.chemical_compound Adenosine Triphosphate Catalytic Domain Phosphorylation Molecular Biology chemistry.chemical_classification Adenosine Triphosphatases Enzyme Catalysis and Regulation Ubiquitin Cell Biology biology.organism_classification Cell biology Protein Subunits Enzyme chemistry Mutagenesis Multiprotein Complexes biology.protein Adenosine triphosphate |
| Zdroj: | The Journal of biological chemistry. 284(27) |
| ISSN: | 1083-351X |
| Popis: | Members of the P(4) 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 P(4)-ATPases to flip phospholipids. P(4)-ATPases form heteromeric complexes with Cdc50 proteins. The primary role of these additional polypeptides is unknown. Here, we show that the affinity of yeast P(4)-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 P(4)-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. |
| Databáze: | OpenAIRE |
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