7PY4

Cryo-EM structure of ATP8B1-CDC50A in E2P autoinhibited state

Summary for 7PY4

• Entry DOI: 10.2210/pdb7py4/pdb
• EMDB information: 13711
• Descriptor: Phospholipid-transporting ATPase IC, Cell cycle control protein 50A, beta-D-mannopyranose-(1-4)-2-acetamido-2-deoxy-beta-D-glucopyranose-(1-4)-2-acetamido-2-deoxy-beta-D-glucopyranose, ... (7 entities in total)
• Functional Keywords: lipid transporter autoinhibition p-type atpase p4-atpase cdc50a, membrane protein
• Biological source: Homo sapiens (Human); More
• Total number of polymer chains: 2
• Total formula weight: 184580.07

Authors

Dieudonne, T.,Abad-Herrera, S.,Juknaviciute Laursen, M.,Lejeune, M.,Stock, C.,Slimani, K.,Jaxel, C.,Lyons, J.A.,Montigny, C.,Gunther Pomorski, T.,Nissen, P.,Lenoir, G. (deposition date: 2021-10-08, release date: 2022-04-27, Last modification date: 2024-11-20)

Primary citation

Dieudonne, T.,Herrera, S.A.,Laursen, M.J.,Lejeune, M.,Stock, C.,Slimani, K.,Jaxel, C.,Lyons, J.A.,Montigny, C.,Pomorski, T.G.,Nissen, P.,Lenoir, G.
Autoinhibition and regulation by phosphoinositides of ATP8B1, a human lipid flippase associated with intrahepatic cholestatic disorders.
Elife, 11:-, 2022

PubMed Abstract: P4-ATPases flip lipids from the exoplasmic to the cytosolic leaflet, thus maintaining lipid asymmetry in eukaryotic cell membranes. Mutations in several human P4-ATPase genes are associated with severe diseases, for example in causing progressive familial intrahepatic cholestasis, a rare inherited disorder progressing toward liver failure. ATP8B1 forms a binary complex with CDC50A and displays a broad specificity to glycerophospholipids, but regulatory mechanisms are unknown. Here, we report functional studies and the cryo-EM structure of the human lipid flippase ATP8B1-CDC50A at 3.1 Å resolution. We find that ATP8B1 is autoinhibited by its N- and C-terminal tails, which form extensive interactions with the catalytic sites and flexible domain interfaces. Consistently, ATP hydrolysis is unleashed by truncation of the C-terminus, but also requires phosphoinositides, most markedly phosphatidylinositol-3,4,5-phosphate (PI(3,4,5)P), and removal of both N- and C-termini results in full activation. Restored inhibition of ATP8B1 truncation constructs with a synthetic peptide mimicking the C-terminal segment further suggests molecular communication between N- and C-termini in the autoinhibition and demonstrates that the regulatory mechanism can be interfered with by exogenous compounds. A recurring (G/A)(Y/F)AFS motif of the C-terminal segment suggests that this mechanism is employed widely across P4-ATPase lipid flippases in plasma membrane and endomembranes.

PubMed: 35416773
DOI: 10.7554/eLife.75272

Experimental method

ELECTRON MICROSCOPY (3.1 Å)