UniProt Accession

 SL9A4_HUMAN; Q6AI14; Q69YK0 

Genbank Protein ID

 AL833048; CR627411; AC007278 

Genbank Nucleotide ID

 CAH10600.1; CAH10500.1 

Protein Name

 Sodium/hydrogen exchanger 4 

Protein Synonyms/Alias

 Na(+)/H(+) exchanger 4; NHE-4; Solute carrier family 9 member 4 

Gene Name

 SLC9A4 

Gene Synonyms/Alias

 NHE4 

Created Date

 July 27, 2013 

Organism

 Homo sapiens (Human) 

NCBI Taxa ID

 9606 

Lysine Modification

Position	Peptide	Type	References
352	QTSYTTIKYFMKMLS	ubiquitination	[1, 2]

Reference

 [1] Tryptic digestion of ubiquitin standards reveals an improved strategy for identifying ubiquitinated proteins by mass spectrometry.
 Denis NJ, Vasilescu J, Lambert JP, Smith JC, Figeys D.
 Proteomics. 2007 Mar;7(6):868-74. [PMID: 17370265]
 [2] hCKSAAP_UbSite: improved prediction of human ubiquitination sites by exploiting amino acid pattern and properties.
 Chen Z, Zhou Y, Song J, Zhang Z.
 Biochim Biophys Acta. 2013 Aug;1834(8):1461-7. [PMID: 23603789] 

Functional Description

 Involved in pH regulation to eliminate acids generated by active metabolism or to counter adverse environmental conditions. Major proton extruding system driven by the inward sodium ion chemical gradient. Plays an important role in signal transduction. May play a specialized role in the kidney in rectifying cell volume in response to extreme fluctuations of hyperosmolar-stimulated cell shrinkage. Is relatively amiloride and ethylisopropylamiloride (EIPA) insensitive. Can be activated under conditions of hyperosmolar-induced cell shrinkage in a sustained intracellular acidification-dependence manner. Activated by 4,4'-diisothiocyanostilbene-2,2'-disulfonic acid (DIDS) in a sustained intracellular acidification-dependence manner. Affects potassium/proton exchange as well as sodium/proton and lithium/proton exchange. In basolateral cell membrane, participates in homeostatic control of intracellular pH, and may play a role in proton extrusion in order to achieve transepithelial HCO3(-) secretion. In apical cell membrane may be involved in mediating sodium absorption. Requires for normal levels of gastric acid secretion, secretory membrane development, parietal cell maturation and/or differentiation and at least secondarily for chief cell differentiation (By similarity). 

Sequence Annotation

 CARBOHYD 342 342 N-linked (GlcNAc...) (Potential).
 CROSSLNK 352 352 Glycyl lysine isopeptide (Lys-Gly)  

Keyword

 Antiport; Cell membrane; Complete proteome; Glycoprotein; Ion transport; Isopeptide bond; Membrane; Phosphoprotein; Polymorphism; Reference proteome; Sodium; Sodium transport; Transmembrane; Transmembrane helix; Transport; Ubl conjugation. 

Sequence Source

 UniProt (SWISSPROT/TrEMBL); GenBank; EMBL 

Protein Length

 798 AA 

Protein Sequence

Gene Ontology

 GO:0016324; C:apical plasma membrane; IEA:UniProtKB-SubCell.
 GO:0016323; C:basolateral plasma membrane; IEA:UniProtKB-SubCell.
 GO:0016021; C:integral to membrane; IEA:UniProtKB-KW.
 GO:0005886; C:plasma membrane; TAS:Reactome.
 GO:0015385; F:sodium:hydrogen antiporter activity; IEA:InterPro.
 GO:0006811; P:ion transport; TAS:Reactome.
 GO:0006885; P:regulation of pH; IEA:InterPro.
 GO:0055085; P:transmembrane transport; TAS:Reactome. 

Interpro

 IPR006153; Cation/H_exchanger.
 IPR018422; Cation/H_exchanger_CPA1.
 IPR001953; Na/H_exchanger_2.
 IPR004709; NaH_exchanger. 

Pfam

 PF00999; Na_H_Exchanger 

SMART

  

PROSITE

  

PRINTS

 PR01084; NAHEXCHNGR.
 PR01086; NAHEXCHNGR2.