| Structural highlights
Function
[CC50A_HUMAN] Accessory component of a P4-ATPase flippase complex which catalyzes the hydrolysis of ATP coupled to the transport of aminophospholipids from the outer to the inner leaflet of various membranes and ensures the maintenance of asymmetric distribution of phospholipids. Phospholipid translocation seems also to be implicated in vesicle formation and in uptake of lipid signaling molecules. The beta subunit may assist in binding of the phospholipid substrate. Required for the proper folding, assembly and ER to Golgi exit of the ATP8A2:TMEM30A flippase complex. ATP8A2:TMEM30A may be involved in regulation of neurite outgrowth, and, reconstituted to liposomes, predomiminantly transports phosphatidylserine (PS) and to a lesser extent phosphatidylethanolamine (PE). The ATP8A1:TMEM30A flippase complex seems to play a role in regulation of cell migration probably involving flippase-mediated translocation of phosphatidylethanolamine (PE) at the plasma membrane. Required for the formation of the ATP8A2, ATP8B1 and ATP8B2 P-type ATPAse intermediate phosphoenzymes. Involved in uptake of platelet-activating factor (PAF), synthetic drug alkylphospholipid edelfosine, and, probably in association with ATP8B1, of perifosine. Also mediate the export of alpha subunits ATP8A1, ATP8B1, ATP8B2, ATP8B4, ATP10A, ATP10B, ATP10D, ATP11A, ATP11B and ATP11C from the ER to other membrane localizations.[1] [2] [3] [4]
Publication Abstract from PubMed
In eukaryotic membranes, P4-ATPases mediate the translocation of phospholipids from the outer to inner leaflet and maintain lipid asymmetry, which is critical for membrane trafficking and signaling pathways. Here we report the cryo-EM structures of six distinct intermediates of the human ATP8A1-CDC50a hetero-complex, at 2.6-3.3 A resolutions, elucidating lipid translocation cycle of this P4-ATPase. ATP-dependent phosphorylation induces a large rotational movement of the actuator domain around the phosphorylation site in the phosphorylation domain, accompanied by lateral shifts of the first and second transmembrane helices, thereby allowing phosphatidylserine binding. The phospholipid head group passes through the hydrophilic cleft, while the acyl chain is exposed toward the lipid environment. These findings advance our understanding of the flippase mechanism and the disease-associated mutants of P4-ATPases.
Cryo-EM structures capture the transport cycle of the P4-ATPase flippase.,Hiraizumi M, Yamashita K, Nishizawa T, Nureki O Science. 2019 Aug 15. pii: science.aay3353. doi: 10.1126/science.aay3353. PMID:31416931[5]
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.
References
- ↑ Munoz-Martinez F, Torres C, Castanys S, Gamarro F. CDC50A plays a key role in the uptake of the anticancer drug perifosine in human carcinoma cells. Biochem Pharmacol. 2010 Sep 15;80(6):793-800. doi: 10.1016/j.bcp.2010.05.017., Epub 2010 May 25. PMID:20510206 doi:http://dx.doi.org/10.1016/j.bcp.2010.05.017
- ↑ van der Velden LM, Wichers CG, van Breevoort AE, Coleman JA, Molday RS, Berger R, Klomp LW, van de Graaf SF. Heteromeric interactions required for abundance and subcellular localization of human CDC50 proteins and class 1 P4-ATPases. J Biol Chem. 2010 Dec 17;285(51):40088-96. doi: 10.1074/jbc.M110.139006. Epub, 2010 Oct 14. PMID:20947505 doi:http://dx.doi.org/10.1074/jbc.M110.139006
- ↑ Bryde S, Hennrich H, Verhulst PM, Devaux PF, Lenoir G, Holthuis JC. CDC50 proteins are critical components of the human class-1 P4-ATPase transport machinery. J Biol Chem. 2010 Dec 24;285(52):40562-72. doi: 10.1074/jbc.M110.139543. Epub, 2010 Oct 20. PMID:20961850 doi:http://dx.doi.org/10.1074/jbc.M110.139543
- ↑ Chen R, Brady E, McIntyre TM. Human TMEM30a promotes uptake of antitumor and bioactive choline phospholipids into mammalian cells. J Immunol. 2011 Mar 1;186(5):3215-25. doi: 10.4049/jimmunol.1002710. Epub 2011, Feb 2. PMID:21289302 doi:http://dx.doi.org/10.4049/jimmunol.1002710
- ↑ Hiraizumi M, Yamashita K, Nishizawa T, Nureki O. Cryo-EM structures capture the transport cycle of the P4-ATPase flippase. Science. 2019 Aug 15. pii: science.aay3353. doi: 10.1126/science.aay3353. PMID:31416931 doi:http://dx.doi.org/10.1126/science.aay3353
|
