2krg | pdb_00002krg
Solution Structure of human sodium/ hydrogen exchange regulatory factor 1(150-358)
Structural highlights
Disease[NHRF1_HUMAN] Defects in SLC9A3R1 are the cause of hypophosphatemic nephrolithiasis/osteoporosis type 2 (NPHLOP2) [MIM:612287]. Hypophosphatemia results from idiopathic renal phosphate loss. It contributes to the pathogenesis of hypophosphatemic urolithiasis (formation of urinary calculi) as well to that of hypophosphatemic osteoporosis (bone demineralization).[1] [2] Function[NHRF1_HUMAN] Scaffold protein that connects plasma membrane proteins with members of the ezrin/moesin/radixin family and thereby helps to link them to the actin cytoskeleton and to regulate their surface expression. Necessary for recycling of internalized ADRB2. Was first known to play a role in the regulation of the activity and subcellular location of SLC9A3. Necessary for cAMP-mediated phosphorylation and inhibition of SLC9A3. May enhance Wnt signaling. May participate in HTR4 targeting to microvilli (By similarity). Involved in the regulation of phosphate reabsorption in the renal proximal tubules.[3] [4] [5] [6] Evolutionary Conservation Check, as determined by ConSurfDB. You may read the explanation of the method and the full data available from ConSurf. Publication Abstract from PubMedThe mammalian Na(+)/H(+) exchange regulatory factor 1 (NHERF1) is a multidomain scaffolding protein essential for regulating the intracellular trafficking and macromolecular assembly of transmembrane ion channels and receptors. NHERF1 consists of tandem PDZ-1, PDZ-2 domains that interact with the cytoplasmic domains of membrane proteins and a C-terminal (CT) domain that binds the membrane-cytoskeleton linker protein ezrin. NHERF1 is held in an autoinhibited state through intramolecular interactions between PDZ2 and the CT domain that also includes a C-terminal PDZ-binding motif (-SNL). We have determined the structures of the isolated and tandem PDZ2CT domains by high resolution NMR using small angle x-ray scattering as constraints. The PDZ2CT structure shows weak intramolecular interactions between the largely disordered CT domain and the PDZ ligand binding site. The structure reveals a novel helix-turn-helix subdomain that is allosterically coupled to the putative PDZ2 domain by a network of hydrophobic interactions. This helical subdomain increases both the stability and the binding affinity of the extended PDZ structure. Using NMR and small angle neutron scattering for joint structure refinement, we demonstrate the release of intramolecular domain-domain interactions in PDZ2CT upon binding to ezrin. Based on the structural information, we show that human disease-causing mutations in PDZ2, R153Q and E225K, have significantly reduced protein stability. Loss of NHERF1 expressed in cells could result in failure to assemble membrane complexes that are important for normal physiological functions. A conformational switch in the scaffolding protein NHERF1 controls autoinhibition and complex formation.,Bhattacharya S, Dai Z, Li J, Baxter S, Callaway DJ, Cowburn D, Bu Z J Biol Chem. 2010 Mar 26;285(13):9981-94. Epub 2009 Dec 30. PMID:20042604[7] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See AlsoReferences
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