View source for 9j52


==CryoEM structure of human XPR1 in complex with phosphate in state B==
<StructureSection load='9j52' size='340' side='right'caption='[[9j52]], [[Resolution|resolution]] 3.10&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[9j52]] is a 2 chain structure with sequence from [https://en.wikipedia.org/wiki/Homo_sapiens Homo sapiens]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=9J52 OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=9J52 FirstGlance]. <br>
</td></tr><tr id='method'><td class="sblockLbl"><b>[[Empirical_models|Method:]]</b></td><td class="sblockDat" id="methodDat">Electron Microscopy, [[Resolution|Resolution]] 3.1&#8491;</td></tr>
<tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=PC1:1,2-DIACYL-SN-GLYCERO-3-PHOSPHOCHOLINE'>PC1</scene>, <scene name='pdbligand=PO4:PHOSPHATE+ION'>PO4</scene></td></tr>
<tr id='resources'><td class="sblockLbl"><b>Resources:</b></td><td class="sblockDat"><span class='plainlinks'>[https://proteopedia.org/fgij/fg.htm?mol=9j52 FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=9j52 OCA], [https://pdbe.org/9j52 PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=9j52 RCSB], [https://www.ebi.ac.uk/pdbsum/9j52 PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=9j52 ProSAT]</span></td></tr>
</table>
== Disease ==
[https://www.uniprot.org/uniprot/S53A1_HUMAN S53A1_HUMAN] Bilateral striopallidodentate calcinosis. The disease is caused by variants affecting the gene represented in this entry.
== Function ==
[https://www.uniprot.org/uniprot/S53A1_HUMAN S53A1_HUMAN] Inorganic ion transporter that mediates phosphate ion export across plasma membrane. Plays a major role in phosphate homeostasis, preventing intracellular phosphate accumulation and possible calcium phosphate precipitation, ultimately preserving calcium signaling. The molecular mechanism of phosphate transport, whether electrogenic, electroneutral or coupled to other ions, remains to be elucidated (By similarity) (PubMed:23791524, PubMed:25938945, PubMed:31043717). Binds inositol hexakisphosphate (Ins6P) and similar inositol polyphosphates, such as 5-diphospho-inositol pentakisphosphate (5-InsP7), important intracellular signaling molecules involved in regulation of phosphate flux (PubMed:27080106).[UniProtKB:Q9Z0U0]<ref>PMID:23791524</ref> <ref>PMID:25938945</ref> <ref>PMID:27080106</ref> <ref>PMID:31043717</ref> 
<div style="background-color:#fffaf0;">
== Publication Abstract from PubMed ==
XPR1 is the sole protein known to transport inorganic phosphate (Pi) out of cells, a function conserved across species from yeast to mammals. Human XPR1 variants lead to cerebral calcium-phosphate deposition and primary familial brain calcification (PFBC), a hereditary neurodegenerative disorder. Here, we present the cryo-EM structure of human XPR1 in both its Pi-unbound and various Pi-bound states. XPR1 features 10 transmembrane alpha-helices forming an ion channel-like structure, with multiple Pi recognition sites along the channel. Pathogenic mutations in two arginine residues, which line the translocation channel, disrupt Pi transport. Molecular dynamics simulations reveal that Pi ion undergoes a stepwise transition through the sequential recognition sites during the transport process. Together with functional analyses, our results suggest that this sequential arrangement allows XPR1 to facilitate Pi ion passage via a "relay" process, and they establish a framework for the interpretation of disease-related mutations and for the development of future therapeutics.

Structural insights into the mechanism of phosphate recognition and transport by XPR1.,Zhang W, Chen Y, Guan Z, Wang Y, Tang M, Du Z, Zhang J, Cheng M, Zuo J, Liu Y, Wang Q, Liu Y, Zhang D, Yin P, Ma L, Liu Z Nat Commun. 2025 Jan 2;16(1):18. doi: 10.1038/s41467-024-55471-9. PMID:39747008<ref>PMID:39747008</ref>

From MEDLINE&reg;/PubMed&reg;, a database of the U.S. National Library of Medicine.<br>
</div>
<div class="pdbe-citations 9j52" style="background-color:#fffaf0;"></div>
== References ==
<references/>
__TOC__
</StructureSection>
[[Category: Homo sapiens]]
[[Category: Large Structures]]
[[Category: Chen YK]]
[[Category: Guan ZY]]
[[Category: Liu Z]]
[[Category: Zhang WH]]