Q14542 · S29A2_HUMAN
- ProteinEquilibrative nucleoside transporter 2
- GeneSLC29A2
- StatusUniProtKB reviewed (Swiss-Prot)
- Organism
- Amino acids456 (go to sequence)
- Protein existenceEvidence at protein level
- Annotation score5/5
Function
function
Bidirectional uniporter involved in the facilitative transport of nucleosides and nucleobases, and contributes to maintaining their cellular homeostasis (PubMed:10722669, PubMed:12527552, PubMed:12590919, PubMed:16214850, PubMed:21795683, PubMed:9396714, PubMed:9478986).
Functions as a Na+-independent, passive transporter (PubMed:9478986).
Involved in the transport of nucleosides such as inosine, adenosine, uridine, thymidine, cytidine and guanosine (PubMed:10722669, PubMed:12527552, PubMed:12590919, PubMed:16214850, PubMed:21795683, PubMed:9396714, PubMed:9478986).
Also able to transport purine nucleobases (hypoxanthine, adenine, guanine) and pyrimidine nucleobases (thymine, uracil) (PubMed:16214850, PubMed:21795683).
Involved in nucleoside transport at basolateral membrane of kidney cells, allowing liver absorption of nucleoside metabolites (PubMed:12527552).
Mediates apical nucleoside uptake into Sertoli cells, thereby regulating the transport of nucleosides in testis across the blood-testis-barrier (PubMed:23639800).
Mediates both the influx and efflux of hypoxanthine in skeletal muscle microvascular endothelial cells to control the amount of intracellular hypoxanthine available for xanthine oxidase-mediated ROS production (By similarity).
Functions as a Na+-independent, passive transporter (PubMed:9478986).
Involved in the transport of nucleosides such as inosine, adenosine, uridine, thymidine, cytidine and guanosine (PubMed:10722669, PubMed:12527552, PubMed:12590919, PubMed:16214850, PubMed:21795683, PubMed:9396714, PubMed:9478986).
Also able to transport purine nucleobases (hypoxanthine, adenine, guanine) and pyrimidine nucleobases (thymine, uracil) (PubMed:16214850, PubMed:21795683).
Involved in nucleoside transport at basolateral membrane of kidney cells, allowing liver absorption of nucleoside metabolites (PubMed:12527552).
Mediates apical nucleoside uptake into Sertoli cells, thereby regulating the transport of nucleosides in testis across the blood-testis-barrier (PubMed:23639800).
Mediates both the influx and efflux of hypoxanthine in skeletal muscle microvascular endothelial cells to control the amount of intracellular hypoxanthine available for xanthine oxidase-mediated ROS production (By similarity).
Isoform 3
Non functional nucleoside transporter protein for adenosine or thymidine transport. Does not express on cell membrane.
Miscellaneous
Transport activity is insensitive to nanomolar concentrations of the inhibitor nitrobenzylmercaptopurine riboside (NBMPR) (PubMed:10722669, PubMed:12590919, PubMed:21795683, PubMed:9396714, PubMed:9478986).
Inhibited by higher concentrations of NBMPR (1uM-10uM) (PubMed:10722669, PubMed:12590919, PubMed:9396714, PubMed:9478986).
Inhibited by higher concentrations of NBMPR (1uM-10uM) (PubMed:10722669, PubMed:12590919, PubMed:9396714, PubMed:9478986).
Catalytic activity
- inosine(in) = inosine(out)This reaction proceeds in the forward and the backward directions.
- adenosine(in) = adenosine(out)This reaction proceeds in the forward and the backward directions.
- uridine(out) = uridine(in)This reaction proceeds in the forward and the backward directions.
- thymidine(in) = thymidine(out)This reaction proceeds in the forward and the backward directions.
- hypoxanthine(out) = hypoxanthine(in)This reaction proceeds in the forward and the backward directions.
- adenine(out) = adenine(in)This reaction proceeds in the forward and the backward directions.
- cytidine(in) = cytidine(out)This reaction proceeds in the forward and the backward directions.
- thymine(out) = thymine(in)This reaction proceeds in the forward and the backward directions.
- uracil(in) = uracil(out)This reaction proceeds in the forward and the backward directions.
- guanine(out) = guanine(in)This reaction proceeds in the forward and the backward directions.
- guanosine(in) = guanosine(out)This reaction proceeds in the forward and the backward directions.
Kinetics
KM | SUBSTRATE | pH | TEMPERATURE[C] | NOTES | EVIDENCE | |
---|---|---|---|---|---|---|
50 μM | inosine | |||||
75.9 μM | adenosine | |||||
140 μM | adenosine | |||||
200 μM | uridine | |||||
250 μM | uridine | |||||
330 μM | uridine | |||||
500 μM | uridine | |||||
710 μM | thymidine | |||||
1500 μM | hypoxanthine | |||||
1800 μM | adenine | |||||
3900 μM | cytidine | |||||
5610 μM | cytidine | |||||
6000 μM | thymine |
Vmax | pH | TEMPERATURE[C] | NOTES | EVIDENCE | |
---|---|---|---|---|---|
72 pmol/min/mg | for inosine uptake | ||||
1147 pmol/min/mg | for adenosine uptake | ||||
2055 pmol/min/mg | for uridine uptake | ||||
2486 pmol/min/mg | for thymidine uptake | ||||
9740 pmol/min/mg | for cytidine uptake |
GO annotations
Keywords
- Biological process
Enzyme and pathway databases
Protein family/group databases
Names & Taxonomy
Protein names
- Recommended nameEquilibrative nucleoside transporter 2
- Short nameshENT2
- Alternative names
Gene names
Organism names
- Organism
- Taxonomic lineageEukaryota > Metazoa > Chordata > Craniata > Vertebrata > Euteleostomi > Mammalia > Eutheria > Euarchontoglires > Primates > Haplorrhini > Catarrhini > Hominidae > Homo
Accessions
- Primary accessionQ14542
- Secondary accessions
Proteomes
Organism-specific databases
Subcellular Location
UniProt Annotation
GO Annotation
Apical cell membrane ; Multi-pass membrane protein
Basolateral cell membrane ; Multi-pass membrane protein
Note: Localized to the apical membrane of Sertoli cells.
Features
Showing features for transmembrane.
Type | ID | Position(s) | Description | |||
---|---|---|---|---|---|---|
Transmembrane | 13-33 | Helical | ||||
Sequence: LVGISFFILGLGTLLPWNFFI | ||||||
Transmembrane | 70-90 | Helical | ||||
Sequence: WVTLLSQLPLLLFTLLNSFLY | ||||||
Transmembrane | 99-119 | Helical | ||||
Sequence: ILGSLLAILLLFALTAALVKV | ||||||
Transmembrane | 124-144 | Helical | ||||
Sequence: GPFFSITMASVCFINSFSAVL | ||||||
Transmembrane | 162-182 | Helical | ||||
Sequence: LFLSGQGLAGIFAALAMLLSM | ||||||
Transmembrane | 193-213 | Helical | ||||
Sequence: LGYFITPCVGILMSIVCYLSL | ||||||
Transmembrane | 291-311 | Helical | ||||
Sequence: WLTALCLVLVFTVTLSVFPAI | ||||||
Transmembrane | 324-344 | Helical | ||||
Sequence: WSQFFNPICCFLLFNIMDWLG | ||||||
Transmembrane | 360-380 | Helical | ||||
Sequence: LLPLLVCLRFLFVPLFMLCHV | ||||||
Transmembrane | 386-406 | Helical | ||||
Sequence: LPILFPQDAYFITFMLLFAVS | ||||||
Transmembrane | 432-452 | Helical | ||||
Sequence: ALMTFFLALGLSCGASLSFLF |
Keywords
- Cellular component
Disease & Variants
Features
Showing features for natural variant, mutagenesis.
Type | ID | Position(s) | Description | |||
---|---|---|---|---|---|---|
Natural variant | VAR_029289 | 5 | decreased nucleoside and nucleobase transport; dbSNP:rs8187643 | |||
Sequence: D → Y | ||||||
Mutagenesis | 48 | No difference in uridine or cytidine uptake. No differences in Km values and lower Vmax values for either uridine or cytidine uptake; when associated with D-57. | ||||
Sequence: N → D | ||||||
Mutagenesis | 57 | No difference in uridine or cytidine uptake. No differences in Km values and lower Vmax values for either uridine or cytidine uptake; when associated with D-48. | ||||
Sequence: N → D | ||||||
Natural variant | VAR_029290 | 68 | no change in nucleoside and nucleobase transport; dbSNP:rs8187644 | |||
Sequence: N → K | ||||||
Natural variant | VAR_029291 | 94 | no change in nucleoside and nucleobase transport; dbSNP:rs8187648 | |||
Sequence: P → L | ||||||
Natural variant | VAR_036822 | 184-186 | decreased inosine and guanosine transport; no change in uridine and hypoxanthine transport | |||
Sequence: SGV → M | ||||||
Mutagenesis | 455 | Reduces drastically localization at the cell surface. No effect on uptake of adenosine and thymidine. Reduces drastically localization at the cell surface and induces an significant reduction of adenosine or thymidine uptake; when associated with R-456. | ||||
Sequence: L → R | ||||||
Mutagenesis | 456 | Reduces drastically localization at the cell surface and induces an significant reduction of adenosine or thymidine uptake; when associated with R-455. | ||||
Sequence: L → R |
Variants
We now provide the "Disease & Variants" viewer in its own tab.
The viewer provides 561 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, glycosylation, modified residue (large scale data), modified residue.
Type | ID | Position(s) | Source | Description | |||
---|---|---|---|---|---|---|---|
Chain | PRO_0000209340 | 1-456 | UniProt | Equilibrative nucleoside transporter 2 | |||
Sequence: MARGDAPRDSYHLVGISFFILGLGTLLPWNFFITAIPYFQARLAGAGNSTARILSTNHTGPEDAFNFNNWVTLLSQLPLLLFTLLNSFLYQCVPETVRILGSLLAILLLFALTAALVKVDMSPGPFFSITMASVCFINSFSAVLQGSLFGQLGTMPSTYSTLFLSGQGLAGIFAALAMLLSMASGVDAETSALGYFITPCVGILMSIVCYLSLPHLKFARYYLANKSSQAQAQELETKAELLQSDENGIPSSPQKVALTLDLDLEKEPESEPDEPQKPGKPSVFTVFQKIWLTALCLVLVFTVTLSVFPAITAMVTSSTSPGKWSQFFNPICCFLLFNIMDWLGRSLTSYFLWPDEDSRLLPLLVCLRFLFVPLFMLCHVPQRSRLPILFPQDAYFITFMLLFAVSNGYLVSLTMCLAPRQVLPHEREVAGALMTFFLALGLSCGASLSFLFKALL | |||||||
Glycosylation | 48 | UniProt | N-linked (GlcNAc...) asparagine | ||||
Sequence: N | |||||||
Glycosylation | 57 | UniProt | N-linked (GlcNAc...) asparagine | ||||
Sequence: N | |||||||
Glycosylation | 225 | UniProt | N-linked (GlcNAc...) asparagine | ||||
Sequence: N | |||||||
Modified residue (large scale data) | 244 | PRIDE | Phosphoserine | ||||
Sequence: S | |||||||
Modified residue (large scale data) | 251 | PRIDE | Phosphoserine | ||||
Sequence: S | |||||||
Modified residue | 252 | UniProt | Phosphoserine | ||||
Sequence: S | |||||||
Modified residue (large scale data) | 252 | PRIDE | Phosphoserine | ||||
Sequence: S |
Post-translational modification
Glycosylated.
Keywords
- PTM
Proteomic databases
PTM databases
Structure
Sequence & Isoforms
- Sequence statusComplete
This entry describes 4 isoforms produced by Alternative splicing.
Q14542-1
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
- SynonymsLong
- Length456
- Mass (Da)50,113
- Last updated2006-10-17 v3
- ChecksumABCBD244306708E1
Q14542-2
- Name2
- SynonymsShort, HNP36
- NoteMay be produced at very low levels due to a premature stop codon in the mRNA, leading to nonsense-mediated mRNA decay.
Q14542-3
- Name3
- SynonymshENT2A
Q14542-4
- Name4
- Differences from canonical
- 246-456: ENGIPSSPQKVALTLDLDLEKEPESEPDEPQKPGKPSVFTVFQKIWLTALCLVLVFTVTLSVFPAITAMVTSSTSPGKWSQFFNPICCFLLFNIMDWLGRSLTSYFLWPDEDSRLLPLLVCLRFLFVPLFMLCHVPQRSRLPILFPQDAYFITFMLLFAVSNGYLVSLTMCLAPRQVLPHEREVAGALMTFFLALGLSCGASLSFLFKALL → LADSAVPCVGLHSHPVRLPRHHSHGDQLHQSWEVESVLQPHLLLPPLQHHGLAGTEPDLLLPVARRGQPAAAPAGLPAVPVRAPLHAVPRAPEVPAAHPLPTGCLLHHLHAALCRF
Sequence caution
Features
Showing features for alternative sequence, sequence conflict.
Type | ID | Position(s) | Description | |||
---|---|---|---|---|---|---|
Alternative sequence | VSP_040728 | 93-202 | in isoform 2 | |||
Sequence: VPETVRILGSLLAILLLFALTAALVKVDMSPGPFFSITMASVCFINSFSAVLQGSLFGQLGTMPSTYSTLFLSGQGLAGIFAALAMLLSMASGVDAETSALGYFITPCVG → AGQGGHEPRTLLLHHHGLRLLHQLLQCSPTGQPLRAAGHHALHLQHPLPQRPGPGWDLCCPCHAPVHGQWRGRRDLCPGVLYHALCGHPHVHRVLPEPASPEVCPLLPGQ | ||||||
Sequence conflict | 200 | in Ref. 1; CAA60380 and 2; AAC39526 | ||||
Sequence: C → Y | ||||||
Alternative sequence | VSP_040729 | 203-456 | in isoform 2 | |||
Sequence: Missing | ||||||
Alternative sequence | VSP_061920 | 246-456 | in isoform 4 | |||
Sequence: ENGIPSSPQKVALTLDLDLEKEPESEPDEPQKPGKPSVFTVFQKIWLTALCLVLVFTVTLSVFPAITAMVTSSTSPGKWSQFFNPICCFLLFNIMDWLGRSLTSYFLWPDEDSRLLPLLVCLRFLFVPLFMLCHVPQRSRLPILFPQDAYFITFMLLFAVSNGYLVSLTMCLAPRQVLPHEREVAGALMTFFLALGLSCGASLSFLFKALL → LADSAVPCVGLHSHPVRLPRHHSHGDQLHQSWEVESVLQPHLLLPPLQHHGLAGTEPDLLLPVARRGQPAAAPAGLPAVPVRAPLHAVPRAPEVPAAHPLPTGCLLHHLHAALCRF | ||||||
Alternative sequence | VSP_040730 | 290-301 | in isoform 3 | |||
Sequence: IWLTALCLVLVF → SPCPSSPPSQPW | ||||||
Alternative sequence | VSP_040731 | 302-456 | in isoform 3 | |||
Sequence: Missing |
Keywords
- Coding sequence diversity
- Technical term
Sequence databases
Nucleotide Sequence | Protein Sequence | Molecule Type | Status | |
---|---|---|---|---|
X86681 EMBL· GenBank· DDBJ | CAA60380.1 EMBL· GenBank· DDBJ | mRNA | Sequence problems. | |
AF029358 EMBL· GenBank· DDBJ | AAC39526.1 EMBL· GenBank· DDBJ | mRNA | ||
AF034102 EMBL· GenBank· DDBJ | AAB97834.1 EMBL· GenBank· DDBJ | mRNA | ||
AK057041 EMBL· GenBank· DDBJ | BAG51849.1 EMBL· GenBank· DDBJ | mRNA | ||
AF401235 EMBL· GenBank· DDBJ | AAK92533.1 EMBL· GenBank· DDBJ | mRNA | ||
AP001107 EMBL· GenBank· DDBJ | - | Genomic DNA | No translation available. | |
CH471076 EMBL· GenBank· DDBJ | EAW74521.1 EMBL· GenBank· DDBJ | Genomic DNA | ||
CH471076 EMBL· GenBank· DDBJ | EAW74519.1 EMBL· GenBank· DDBJ | Genomic DNA | ||
CH471076 EMBL· GenBank· DDBJ | EAW74522.1 EMBL· GenBank· DDBJ | Genomic DNA | ||
BC093634 EMBL· GenBank· DDBJ | AAH93634.1 EMBL· GenBank· DDBJ | mRNA |