TY - JOUR
T1 - A High and Phosphatidylinositol-4-phosphate (PI4P)-dependent ATPase Activity for the Drs2p/Cdc50p Flippase after Removal of its N- and C-terminal Extensions
AU - Azouaoui, Hassina
AU - Montigny, Cedric
AU - Dieudonné, Thibaud
AU - Champeil, Philippe
AU - Jacquot, Aurore
AU - Vázquez-Ibar, José Luis
AU - le Maréchal, Pierre
AU - Ulstrup, Jakob
AU - Ash, Miriam-Rose
AU - Lyons, Joseph A
AU - Nissen, Poul
AU - Lenoir, Guillaume
N1 - Copyright © 2017, The American Society for Biochemistry and Molecular Biology.
PY - 2017/5/12
Y1 - 2017/5/12
N2 - P4-ATPases, also known as phospholipid flippases, are responsible for creating and maintaining transbilayer lipid asymmetry in eukaryotic cell membranes. Here, we use limited proteolysis to investigate the role of the N and C termini in ATP hydrolysis and auto-inhibition of the yeast flippase Drs2p-Cdc50p. We show that limited proteolysis of the detergent-solubilized and purified yeast flippase may result in more than 1 order of magnitude increase of its ATPase activity, which remains dependent on phosphatidylinositol 4-phosphate (PI4P), a regulator of this lipid flippase, and specific to a phosphatidylserine substrate. Using thrombin as the protease, Cdc50p remains intact and in complex with Drs2p, which is cleaved at two positions, namely after Arg
104 and after Arg
1290, resulting in a homogeneous sample lacking 104 and 65 residues from its N and C termini, respectively. Removal of the 1291-1302-amino acid region of the C-terminal extension is critical for relieving the auto-inhibition of full-length Drs2p, whereas the 1-104 N-terminal residues have an additional but more modest significance for activity. The present results therefore reveal that trimming off appropriate regions of the terminal extensions of Drs2p can greatly increase its ATPase activity in the presence of PI4P and demonstrate that relief of such auto-inhibition remains compatible with subsequent regulation by PI4P. These experiments suggest that activation of the Drs2p-Cdc50p flippase follows a multistep mechanism, with preliminary release of a number of constraints, possibly through the binding of regulatory proteins in the trans-Golgi network, followed by full activation by PI4P.
AB - P4-ATPases, also known as phospholipid flippases, are responsible for creating and maintaining transbilayer lipid asymmetry in eukaryotic cell membranes. Here, we use limited proteolysis to investigate the role of the N and C termini in ATP hydrolysis and auto-inhibition of the yeast flippase Drs2p-Cdc50p. We show that limited proteolysis of the detergent-solubilized and purified yeast flippase may result in more than 1 order of magnitude increase of its ATPase activity, which remains dependent on phosphatidylinositol 4-phosphate (PI4P), a regulator of this lipid flippase, and specific to a phosphatidylserine substrate. Using thrombin as the protease, Cdc50p remains intact and in complex with Drs2p, which is cleaved at two positions, namely after Arg
104 and after Arg
1290, resulting in a homogeneous sample lacking 104 and 65 residues from its N and C termini, respectively. Removal of the 1291-1302-amino acid region of the C-terminal extension is critical for relieving the auto-inhibition of full-length Drs2p, whereas the 1-104 N-terminal residues have an additional but more modest significance for activity. The present results therefore reveal that trimming off appropriate regions of the terminal extensions of Drs2p can greatly increase its ATPase activity in the presence of PI4P and demonstrate that relief of such auto-inhibition remains compatible with subsequent regulation by PI4P. These experiments suggest that activation of the Drs2p-Cdc50p flippase follows a multistep mechanism, with preliminary release of a number of constraints, possibly through the binding of regulatory proteins in the trans-Golgi network, followed by full activation by PI4P.
KW - Journal Article
UR - http://www.scopus.com/inward/record.url?scp=85019412921&partnerID=8YFLogxK
U2 - 10.1074/jbc.M116.751487
DO - 10.1074/jbc.M116.751487
M3 - Journal article
C2 - 28302728
SN - 0021-9258
VL - 292
SP - 7954
EP - 7970
JO - Journal of Biological Chemistry
JF - Journal of Biological Chemistry
IS - 19
ER -