A high-yield co-expression system for the purification of an intact Drs2p-Cdc50p lipid flippase complex, critically dependent on and stabilized by phosphatidylinositol-4-phosphate

PLoS One. 2014 Nov 13;9(11):e112176. doi: 10.1371/journal.pone.0112176. eCollection 2014.


P-type ATPases from the P4 subfamily (P4-ATPases) are energy-dependent transporters, which are thought to establish lipid asymmetry in eukaryotic cell membranes. Together with their Cdc50 accessory subunits, P4-ATPases couple ATP hydrolysis to lipid transport from the exoplasmic to the cytoplasmic leaflet of plasma membranes, late Golgi membranes, and endosomes. To gain insights into the structure and function of these important membrane pumps, robust protocols for expression and purification are required. In this report, we present a procedure for high-yield co-expression of a yeast flippase, the Drs2p-Cdc50p complex. After recovery of yeast membranes expressing both proteins, efficient purification was achieved in a single step by affinity chromatography on streptavidin beads, yielding ∼ 1-2 mg purified Drs2p-Cdc50p complex per liter of culture. Importantly, the procedure enabled us to recover a fraction that mainly contained a 1:1 complex, which was assessed by size-exclusion chromatography and mass spectrometry. The functional properties of the purified complex were examined, including the dependence of its catalytic cycle on specific lipids. The dephosphorylation rate was stimulated in the simultaneous presence of the transported substrate, phosphatidylserine (PS), and the regulatory lipid phosphatidylinositol-4-phosphate (PI4P), a phosphoinositide that plays critical roles in membrane trafficking events from the trans-Golgi network (TGN). Likewise, overall ATP hydrolysis by the complex was critically dependent on the simultaneous presence of PI4P and PS. We also identified a prominent role for PI4P in stabilization of the Drs2p-Cdc50p complex towards temperature- or C12E8-induced irreversible inactivation. These results indicate that the Drs2p-Cdc50p complex remains functional after affinity purification and that PI4P as a cofactor tightly controls its stability and catalytic activity. This work offers appealing perspectives for detailed structural and functional characterization of the Drs2p-Cdc50p lipid transport mechanism.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Calcium-Transporting ATPases / genetics
  • Calcium-Transporting ATPases / isolation & purification
  • Calcium-Transporting ATPases / metabolism*
  • Phosphatidylinositol Phosphates / metabolism*
  • Saccharomyces cerevisiae / metabolism*
  • Saccharomyces cerevisiae Proteins / genetics
  • Saccharomyces cerevisiae Proteins / isolation & purification
  • Saccharomyces cerevisiae Proteins / metabolism*


  • CDC50 protein, S cerevisiae
  • DRS2 protein, S cerevisiae
  • Phosphatidylinositol Phosphates
  • Saccharomyces cerevisiae Proteins
  • phosphatidylinositol 4-phosphate
  • Calcium-Transporting ATPases

Grant support

This work was supported by a grant from the Agence Nationale pour la Recherche (ANR Blanc program MIT-2M to MlM and CM) and by the French Infrastructure for Integrated Structural Biology (FRISBI, ANR-10-INSB-05-01). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.