Q86UD5 · SL9B2_HUMAN
- ProteinSodium/hydrogen exchanger 9B2
- GeneSLC9B2
- StatusUniProtKB reviewed (Swiss-Prot)
- Organism
- Amino acids537 (go to sequence)
- Protein existenceEvidence at protein level
- Annotation score5/5
Function
function
Uses the proton gradient/membrane potential to extrude sodium (PubMed:22948142).
Contributes to the regulation of intracellular pH and sodium homeostasis (By similarity).
Also able to mediate Na+/Li+ antiporter activity in kidney (PubMed:22948142).
May play a physiological role in renal tubular function and blood pressure homeostasis (By similarity).
Plays an important role for insulin secretion and clathrin-mediated endocytosis in beta-cells (By similarity).
Involved in sperm motility and fertility (By similarity).
It is controversial whether SLC9B2 plays a role in osteoclast differentiation or not (By similarity).
Miscellaneous
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).
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
Inhibited by phloretin (PubMed:18000046, PubMed:36177733).
Kinetics
KM | SUBSTRATE | pH | TEMPERATURE[C] | NOTES | EVIDENCE | |
---|---|---|---|---|---|---|
33 mM | Na+ | |||||
67 mM | Li+ |
Features
Showing features for binding site.
GO annotations
Keywords
- Biological process
- Ligand
Enzyme and pathway databases
Protein family/group databases
Names & Taxonomy
Protein names
- Recommended nameSodium/hydrogen exchanger 9B2
- Alternative names
Gene names
Organism names
- Organism
- Taxonomic lineageEukaryota > Metazoa > Chordata > Craniata > Vertebrata > Euteleostomi > Mammalia > Eutheria > Euarchontoglires > Primates > Haplorrhini > Catarrhini > Hominidae > Homo
Accessions
- Primary accessionQ86UD5
- Secondary accessions
Proteomes
Organism-specific databases
Subcellular Location
Features
Showing features for topological domain, transmembrane.
Type | ID | Position(s) | Description | |||
---|---|---|---|---|---|---|
Topological domain | 1-86 | Cytoplasmic | ||||
Sequence: MGDEDKRITYEDSEPSTGMNYTPSMHQEAQEETVMKLKGIDANEPTEGSILLKSSEKKLQETPTEANHVQRLRQMLACPPHGLLDR | ||||||
Transmembrane | 87-104 | Helical; Name=1 | ||||
Sequence: VITNVTIIVLLWAVVWSI | ||||||
Topological domain | 105-113 | Extracellular | ||||
Sequence: TGSECLPGG | ||||||
Transmembrane | 114-133 | Helical; Name=2 | ||||
Sequence: NLFGIIILFYCAIIGGKLLG | ||||||
Topological domain | 134-144 | Cytoplasmic | ||||
Sequence: LIKLPTLPPLP | ||||||
Transmembrane | 145-161 | Helical; Name=3 | ||||
Sequence: SLLGMLLAGFLIRNIPV | ||||||
Topological domain | 162-171 | Extracellular | ||||
Sequence: INDNVQIKHK | ||||||
Transmembrane | 172-189 | Helical; Name=4 | ||||
Sequence: WSSSLRSIALSIILVRAG | ||||||
Topological domain | 190-200 | Cytoplasmic | ||||
Sequence: LGLDSKALKKL | ||||||
Transmembrane | 201-227 | Helical; Name=5 | ||||
Sequence: KGVCVRLSMGPCIVEACTSALLAHYLL | ||||||
Topological domain | 228-233 | Extracellular | ||||
Sequence: GLPWQW | ||||||
Transmembrane | 234-242 | Helical; Name=6 | ||||
Sequence: GFILGFVLG | ||||||
Topological domain | 243-270 | Cytoplasmic | ||||
Sequence: AVSPAVVVPSMLLLQGGGYGVEKGVPTL | ||||||
Transmembrane | 271-290 | Helical; Name=7 | ||||
Sequence: LMAAGSFDDILAITGFNTCL | ||||||
Topological domain | 291-300 | Extracellular | ||||
Sequence: GIAFSTGSTV | ||||||
Transmembrane | 301-324 | Helical; Name=8 | ||||
Sequence: FNVLRGVLEVVIGVATGSVLGFFI | ||||||
Topological domain | 325-339 | Cytoplasmic | ||||
Sequence: QYFPSRDQDKLVCKR | ||||||
Transmembrane | 340-357 | Helical; Name=9 | ||||
Sequence: TFLVLGLSVLAVFSSVHF | ||||||
Topological domain | 358-361 | Extracellular | ||||
Sequence: GFPG | ||||||
Transmembrane | 362-373 | Helical; Name=10 | ||||
Sequence: SGGLCTLVMAFL | ||||||
Topological domain | 374-390 | Cytoplasmic | ||||
Sequence: AGMGWTSEKAEVEKIIA | ||||||
Transmembrane | 391-411 | Helical; Name=11 | ||||
Sequence: VAWDIFQPLLFGLIGAEVSIA | ||||||
Topological domain | 412-417 | Extracellular | ||||
Sequence: SLRPET | ||||||
Transmembrane | 418-440 | Helical; Name=12 | ||||
Sequence: VGLCVATVGIAVLIRILTTFLMV | ||||||
Topological domain | 441-461 | Cytoplasmic | ||||
Sequence: CFAGFNLKEKIFISFAWLPKA | ||||||
Transmembrane | 462-473 | Helical; Name=13 | ||||
Sequence: TVQAAIGSVALD | ||||||
Topological domain | 474-486 | Extracellular | ||||
Sequence: TARSHGEKQLEDY | ||||||
Transmembrane | 487-509 | Helical; Name=14 | ||||
Sequence: GMDVLTVAFLSILITAPIGSLLI | ||||||
Topological domain | 510-537 | Cytoplasmic | ||||
Sequence: GLLGPRLLQKVEHQNKDEEVQGETSVQV |
Keywords
- Cellular component
Disease & Variants
Features
Showing features for mutagenesis, natural variant.
Type | ID | Position(s) | Description | |||
---|---|---|---|---|---|---|
Mutagenesis | 47 | Decreases Na+ Li+/H+ antiporter activity. | ||||
Sequence: E → A or K | ||||||
Mutagenesis | 56 | Decreases Na+ Li+/H+ antiporter activity. | ||||
Sequence: E → A or K | ||||||
Mutagenesis | 57 | Does not affect Na+ Li+/H+ antiporter activity; when associated with A-58. | ||||
Sequence: K → A | ||||||
Mutagenesis | 57 | Decreases Na+ Li+/H+ antiporter activity; when associated with K-58. | ||||
Sequence: K → E | ||||||
Mutagenesis | 58 | Does not affect tNa+ Li+/H+ antiporter activity; when associated with A-57. | ||||
Sequence: K → A | ||||||
Mutagenesis | 58 | Decreases Na+ Li+/H+ antiporter activity; when associated with K-57. | ||||
Sequence: K → E | ||||||
Natural variant | VAR_042751 | 159 | in dbSNP:rs7672710 | |||
Sequence: I → T | ||||||
Natural variant | VAR_042752 | 161 | in dbSNP:rs7672707 | |||
Sequence: V → A | ||||||
Mutagenesis | 215 | Abolishes Na+ Li+/H+ antiporter activity. Shifts the specificity of the transporter from Na+ to Li+; when associated with E-432. Decreases plasma membrane localization. Partially retained in the ER; when associated with E-432. | ||||
Sequence: E → R | ||||||
Mutagenesis | 238 | Abolishes Na+ Li+/H+ antiporter activity. Changes subcellular localization. Retained in the ER. | ||||
Sequence: G → R | ||||||
Mutagenesis | 240 | Does not affect plasma membrane localization. Change in the substrate specificity with a preference for Li+ over Na+. | ||||
Sequence: V → L | ||||||
Mutagenesis | 246 | Does not affect plasma membrane localization. Less sensitive to phloretin inhibition. | ||||
Sequence: P → A | ||||||
Mutagenesis | 246 | Does not affect plasma membrane localization. Abolishes antiporter activity. Less sensitive to phloretin inhibition. | ||||
Sequence: P → G | ||||||
Mutagenesis | 246 | Does not affect plasma membrane localization. Less sensitive to phloretin inhibition. | ||||
Sequence: P → S | ||||||
Mutagenesis | 246 | Does not affect plasma membrane localization. Less sensitive to phloretin inhibition. | ||||
Sequence: P → T | ||||||
Mutagenesis | 278 | Abolishes Na+ Li+/H+ antiporter activity. Does not affect plasma membrane localization. | ||||
Sequence: D → G | ||||||
Mutagenesis | 278-279 | Loss of ion transport activity; Does not rescue insulin secretion defect induced by knockdown of SLC9B2 in Min6 cells. | ||||
Sequence: DD → CC | ||||||
Natural variant | VAR_042753 | 357 | in dbSNP:rs2276976 | |||
Sequence: F → C | ||||||
Mutagenesis | 382 | Does not affect plasma membrane localization. Decreases the substrate specificity for Li+. | ||||
Sequence: K → E | ||||||
Mutagenesis | 406 | Does not affect plasma membrane localization. Decreases Na+ Li+/H+ antiporter activity. | ||||
Sequence: A → E | ||||||
Mutagenesis | 432 | Abolishes Na+ Li+/H+ antiporter activity. Shifts the specificity from Na+ to Li+; when associated with R-215. Decreases plasma membrane localization; when associated with R-215. Partially retained in the ER; when associated with R-215. | ||||
Sequence: R → E | ||||||
Mutagenesis | 432 | Loss of ion transport activity. | ||||
Sequence: R → K or H | ||||||
Mutagenesis | 432 | Does not affect plasma membrane localization. Decreases the substrate specificity for Li+. | ||||
Sequence: R → Q |
Variants
We now provide the "Disease & Variants" viewer in its own tab.
The viewer provides 689 variants from UniProt as well as other sources including ClinVar and dbSNP.
Organism-specific databases
Miscellaneous
Chemistry
Genetic variation databases
PTM/Processing
Features
Showing features for chain, modified residue, modified residue (large scale data).
Type | ID | Position(s) | Source | Description | |||
---|---|---|---|---|---|---|---|
Chain | PRO_0000331270 | 1-537 | UniProt | Sodium/hydrogen exchanger 9B2 | |||
Sequence: MGDEDKRITYEDSEPSTGMNYTPSMHQEAQEETVMKLKGIDANEPTEGSILLKSSEKKLQETPTEANHVQRLRQMLACPPHGLLDRVITNVTIIVLLWAVVWSITGSECLPGGNLFGIIILFYCAIIGGKLLGLIKLPTLPPLPSLLGMLLAGFLIRNIPVINDNVQIKHKWSSSLRSIALSIILVRAGLGLDSKALKKLKGVCVRLSMGPCIVEACTSALLAHYLLGLPWQWGFILGFVLGAVSPAVVVPSMLLLQGGGYGVEKGVPTLLMAAGSFDDILAITGFNTCLGIAFSTGSTVFNVLRGVLEVVIGVATGSVLGFFIQYFPSRDQDKLVCKRTFLVLGLSVLAVFSSVHFGFPGSGGLCTLVMAFLAGMGWTSEKAEVEKIIAVAWDIFQPLLFGLIGAEVSIASLRPETVGLCVATVGIAVLIRILTTFLMVCFAGFNLKEKIFISFAWLPKATVQAAIGSVALDTARSHGEKQLEDYGMDVLTVAFLSILITAPIGSLLIGLLGPRLLQKVEHQNKDEEVQGETSVQV | |||||||
Modified residue | 49 | UniProt | Phosphoserine | ||||
Sequence: S | |||||||
Modified residue (large scale data) | 49 | PRIDE | Phosphoserine | ||||
Sequence: S |
Keywords
- PTM
Proteomic databases
PTM databases
Expression
Interaction
Subunit
Dimerization is essential for SLC9B2 activity (By similarity).
Lipids seem to play a role in the stabilization of the dimerization subdomain (By similarity).
Binary interactions
Type | Entry 1 | Entry 2 | Number of experiments | Intact | |
---|---|---|---|---|---|
BINARY | Q86UD5 | PGRMC2 O15173 | 3 | EBI-9916342, EBI-1050125 |
Protein-protein interaction databases
Miscellaneous
Structure
Family & Domains
Features
Showing features for region, compositional bias.
Type | ID | Position(s) | Description | |||
---|---|---|---|---|---|---|
Region | 1-28 | Disordered | ||||
Sequence: MGDEDKRITYEDSEPSTGMNYTPSMHQE | ||||||
Compositional bias | 13-28 | Polar residues | ||||
Sequence: SEPSTGMNYTPSMHQE |
Sequence similarities
Keywords
- Domain
Phylogenomic databases
Family and domain databases
Sequence & Isoform
- Sequence statusComplete
This entry describes 2 isoforms produced by Alternative splicing.
Q86UD5-1
This isoform has been chosen as the canonical sequence. All positional information in this entry refers to it. This is also the sequence that appears in the downloadable versions of the entry.
- Name1
- Length537
- Mass (Da)57,564
- Last updated2005-08-30 v2
- Checksum85A8BDA60ABE2587
Q86UD5-2
- Name2
Computationally mapped potential isoform sequences
There are 5 potential isoforms mapped to this entry
Entry | Entry name | Gene name | Length | ||
---|---|---|---|---|---|
D6RGJ7 | D6RGJ7_HUMAN | SLC9B2 | 143 | ||
D6R9P2 | D6R9P2_HUMAN | SLC9B2 | 112 | ||
B7Z676 | B7Z676_HUMAN | SLC9B2 | 417 | ||
E9PE63 | E9PE63_HUMAN | SLC9B2 | 480 | ||
A0A0C4DGB3 | A0A0C4DGB3_HUMAN | SLC9B2 | 354 |
Features
Showing features for compositional bias, alternative sequence.
Type | ID | Position(s) | Description | |||
---|---|---|---|---|---|---|
Compositional bias | 13-28 | Polar residues | ||||
Sequence: SEPSTGMNYTPSMHQE | ||||||
Alternative sequence | VSP_033152 | 420-502 | in isoform 2 | |||
Sequence: LCVATVGIAVLIRILTTFLMVCFAGFNLKEKIFISFAWLPKATVQAAIGSVALDTARSHGEKQLEDYGMDVLTVAFLSILITA → SADSITGNFGTERPKLLGPPSTQLRFHFFHIQLST | ||||||
Alternative sequence | VSP_033153 | 503-537 | in isoform 2 | |||
Sequence: Missing |
Keywords
- Coding sequence diversity
- Technical term
Sequence databases
Nucleotide Sequence | Protein Sequence | Molecule Type | Status | |
---|---|---|---|---|
AK172823 EMBL· GenBank· DDBJ | BAD18790.1 EMBL· GenBank· DDBJ | mRNA | ||
AC097485 EMBL· GenBank· DDBJ | - | Genomic DNA | No translation available. | |
CH471057 EMBL· GenBank· DDBJ | EAX06159.1 EMBL· GenBank· DDBJ | Genomic DNA | ||
BC009732 EMBL· GenBank· DDBJ | AAH09732.1 EMBL· GenBank· DDBJ | mRNA | ||
BC047447 EMBL· GenBank· DDBJ | AAH47447.2 EMBL· GenBank· DDBJ | mRNA |