A4IHB9 · SL9B2_XENTR
- ProteinSodium/hydrogen exchanger 9B2
- Geneslc9b2
- StatusUniProtKB reviewed (Swiss-Prot)
- Amino acids539 (go to sequence)
- Protein existenceEvidence at transcript level
- Annotation score5/5
Function
function
Electroneutral Na+ Li+/H+ antiporter that extrudes Na+ or Li+ in exchange for external protons across the membrane (By similarity).
Uses the proton gradient/membrane potential to extrude sodium (By similarity).
Contributes to the regulation of intracellular pH and sodium homeostasis (By similarity).
Also able to mediate Na+/Li+ antiporter activity in kidney (By similarity).
Uses the proton gradient/membrane potential to extrude sodium (By similarity).
Contributes to the regulation of intracellular pH and sodium homeostasis (By similarity).
Also able to mediate Na+/Li+ antiporter activity in kidney (By similarity).
Miscellaneous
The subcellular localization of SLC9B2 remains controversial. Was initially thought to partially localize to mitochondria. However SLC9B2 does not seem to contain a mitochondrial targeting sequence. It was later established that its localizes predominantly in plasma membrane or intracellularly to endosomes and lysosomes (By similarity).
In another recent study, endogenous SLC9B2 in the distal tubular cell line mpkDCT4 is detected in recycling endosomes but absent in plasma membrane (By similarity).
In another recent study, endogenous SLC9B2 in the distal tubular cell line mpkDCT4 is detected in recycling endosomes but absent in plasma membrane (By similarity).
Catalytic activity
- H+(in) + Li+(out) = H+(out) + Li+(in)
- Li+(in) + Na+(out) = Li+(out) + Na+(in)
- H+(out) + Na+(in) = H+(in) + Na+(out)
Activity regulation
Allosterically inhibited by the N-terminal domain. Inhibited by phloretin.
Features
Showing features for binding site.
GO annotations
Aspect | Term | |
---|---|---|
Cellular Component | apical plasma membrane | |
Cellular Component | basolateral plasma membrane | |
Cellular Component | mitochondrial membrane | |
Cellular Component | recycling endosome | |
Cellular Component | recycling endosome membrane | |
Cellular Component | synaptic vesicle membrane | |
Molecular Function | antiporter activity | |
Molecular Function | metal ion binding | |
Biological Process | proton transmembrane transport | |
Biological Process | sodium ion homeostasis | |
Biological Process | sodium ion transport |
Keywords
- Biological process
- Ligand
Enzyme and pathway databases
Names & Taxonomy
Protein names
- Recommended nameSodium/hydrogen exchanger 9B2
- Alternative names
Gene names
Organism names
- Taxonomic lineageEukaryota > Metazoa > Chordata > Craniata > Vertebrata > Euteleostomi > Amphibia > Batrachia > Anura > Pipoidea > Pipidae > Xenopodinae > Xenopus > Silurana
Accessions
- Primary accessionA4IHB9
Proteomes
Organism-specific databases
Subcellular Location
UniProt Annotation
GO Annotation
Cell membrane ; Multi-pass membrane protein
Mitochondrion membrane ; Multi-pass membrane protein
Endosome membrane ; Multi-pass membrane protein
Recycling endosome membrane ; Multi-pass membrane protein
Cytoplasmic vesicle, secretory vesicle, synaptic vesicle membrane ; Multi-pass membrane protein
Basolateral cell membrane ; Multi-pass membrane protein
Apical cell membrane ; Multi-pass membrane protein
Features
Showing features for topological domain, transmembrane.
Type | ID | Position(s) | Description | |||
---|---|---|---|---|---|---|
Topological domain | 1-94 | Cytoplasmic | ||||
Sequence: MEDSLFSVDKAGPGKDASAASADCNHMVAEDGIITEQHKEIPLVALKVPDGHAPIDECELLNSDDQLPKGSQNQTNICMRIRAFACPPQGCFSL | ||||||
Transmembrane | 95-112 | Helical; Name=1 | ||||
Sequence: AITNVTMVILIWAVVWSI | ||||||
Topological domain | 113-121 | Extracellular | ||||
Sequence: TGPECLPGG | ||||||
Transmembrane | 122-141 | Helical; Name=2 | ||||
Sequence: NLFGILALLFSAALGGKLIS | ||||||
Topological domain | 142-152 | Cytoplasmic | ||||
Sequence: LIKIPSLPPLP | ||||||
Transmembrane | 153-169 | Helical; Name=3 | ||||
Sequence: PLLGMLLAGFLIRNIPV | ||||||
Topological domain | 170-179 | Extracellular | ||||
Sequence: ITDQVQIHHK | ||||||
Transmembrane | 180-197 | Helical; Name=4 | ||||
Sequence: WSAALRNIALAIILVRAG | ||||||
Topological domain | 198-208 | Cytoplasmic | ||||
Sequence: LGLDPKALRKL | ||||||
Transmembrane | 209-235 | Helical; Name=5 | ||||
Sequence: KAVCLRLSFGPCVVESCTAAVVSHFIM | ||||||
Topological domain | 236-241 | Extracellular | ||||
Sequence: GFPLTW | ||||||
Transmembrane | 242-250 | Helical; Name=6 | ||||
Sequence: GFMLGFVLG | ||||||
Topological domain | 251-278 | Cytoplasmic | ||||
Sequence: AVSPAVVVPSMLILQKEGFGVDKGIPTL | ||||||
Transmembrane | 279-298 | Helical; Name=7 | ||||
Sequence: LMAAGSFDDVLAITGFNTCL | ||||||
Topological domain | 299-308 | Extracellular | ||||
Sequence: GMAFSSGSTL | ||||||
Transmembrane | 309-332 | Helical; Name=8 | ||||
Sequence: NTIVRGVLEVVVGIAAGLLFGFFL | ||||||
Topological domain | 333-347 | Cytoplasmic | ||||
Sequence: HYFPSKDQENLKGKR | ||||||
Transmembrane | 348-365 | Helical; Name=9 | ||||
Sequence: SYLILALSVFAVFGSLYF | ||||||
Topological domain | 366-369 | Extracellular | ||||
Sequence: GFPG | ||||||
Transmembrane | 370-381 | Helical; Name=10 | ||||
Sequence: SGGLCTLVMAFL | ||||||
Topological domain | 382-398 | Cytoplasmic | ||||
Sequence: AGIGWSTDKTVVEDIIA | ||||||
Transmembrane | 399-419 | Helical; Name=11 | ||||
Sequence: VSWDIFQPLLFGLIGAEISVA | ||||||
Topological domain | 420-425 | Extracellular | ||||
Sequence: SLKPET | ||||||
Transmembrane | 426-448 | Helical; Name=12 | ||||
Sequence: VGLCTATLIIALIIRICISFLMV | ||||||
Topological domain | 449-469 | Cytoplasmic | ||||
Sequence: CFSGFSLKEKIFISLAWMPKA | ||||||
Transmembrane | 470-481 | Helical; Name=13 | ||||
Sequence: TVQAAIGSVALD | ||||||
Topological domain | 482-494 | Extracellular | ||||
Sequence: TARTLENKQFEDY | ||||||
Transmembrane | 495-517 | Helical; Name=14 | ||||
Sequence: GMDVLTVAFLGILVTAPIGALVI | ||||||
Topological domain | 518-539 | Cytoplasmic | ||||
Sequence: GLTGPKMLEKSESRTVTEEGSV |
Keywords
- Cellular component
PTM/Processing
Features
Showing features for chain.
Type | ID | Position(s) | Description | |||
---|---|---|---|---|---|---|
Chain | PRO_0000331273 | 1-539 | Sodium/hydrogen exchanger 9B2 | |||
Sequence: MEDSLFSVDKAGPGKDASAASADCNHMVAEDGIITEQHKEIPLVALKVPDGHAPIDECELLNSDDQLPKGSQNQTNICMRIRAFACPPQGCFSLAITNVTMVILIWAVVWSITGPECLPGGNLFGILALLFSAALGGKLISLIKIPSLPPLPPLLGMLLAGFLIRNIPVITDQVQIHHKWSAALRNIALAIILVRAGLGLDPKALRKLKAVCLRLSFGPCVVESCTAAVVSHFIMGFPLTWGFMLGFVLGAVSPAVVVPSMLILQKEGFGVDKGIPTLLMAAGSFDDVLAITGFNTCLGMAFSSGSTLNTIVRGVLEVVVGIAAGLLFGFFLHYFPSKDQENLKGKRSYLILALSVFAVFGSLYFGFPGSGGLCTLVMAFLAGIGWSTDKTVVEDIIAVSWDIFQPLLFGLIGAEISVASLKPETVGLCTATLIIALIIRICISFLMVCFSGFSLKEKIFISLAWMPKATVQAAIGSVALDTARTLENKQFEDYGMDVLTVAFLGILVTAPIGALVIGLTGPKMLEKSESRTVTEEGSV |
Proteomic databases
Interaction
Subunit
Homodimer; dimerization is essential for SLC9B2 activity. Lipids seem to play a role in the stabilization of the dimerization subdomain.
Protein-protein interaction databases
Structure
Family & Domains
Sequence similarities
Keywords
- Domain
Phylogenomic databases
Family and domain databases
Sequence
- Sequence statusComplete
- Length539
- Mass (Da)57,148
- Last updated2007-05-01 v1
- Checksum53E7582EA2CA634C
Keywords
- Technical term
Sequence databases
Nucleotide Sequence | Protein Sequence | Molecule Type | Status | |
---|---|---|---|---|
BC135456 EMBL· GenBank· DDBJ | AAI35457.1 EMBL· GenBank· DDBJ | mRNA |