Equilibrative nucleoside transporter 3

SLC29A3
Identifiers
Aliases	SLC29A3, ENT3, HCLAP, HJCD, PHID, solute carrier family 29 member 3
External IDs	OMIM: 612373; MGI: 1918529; GeneCards: SLC29A3
Gene location (Human)
Chr.	Chromosome 10 (human)
End	71,381,423 bp
Gene location (Mouse)
Chr.	Chromosome 10 (mouse)
End	60,588,573 bp
RNA expression pattern
	Top expressed in
	gonad; ; mucosa of urinary bladder; ; placenta; ; oocyte; ; right ovary; ; granulocyte; ; testicle; ; mononuclear cell; ; monocyte; ; left ovary;
	Top expressed in
	right kidney; ; proximal tubule; ; human kidney; ; stroma of bone marrow; ; lumbar subsegment of spinal cord; ; lacrimal gland; ; external carotid artery; ; internal carotid artery; ; lymph node; ; granulocyte;
	More reference expression data
	n/a
Gene ontology
Molecular function	nucleoside transmembrane transporter activity; protein binding;
Cellular component	integral component of membrane; lysosomal membrane; endosome; lysosome; membrane; late endosome membrane; Golgi apparatus; intracellular membrane-bounded organelle; plasma membrane;
Biological process	nucleoside transport; nucleoside transmembrane transport; transport;
	Sources:Amigo / QuickGO
Orthologs
Databases	NCBI: entry; OMA: entry
	55315
	71279
	ENSG00000198246
	ENSMUSG00000020100
	Q9BZD2
	Q99P65
	NM_001174098; NM_018344; NM_001363518
	NM_023596
	NP_001167569; NP_060814; NP_001350447
	NP_076085
	Wikidata
View/Edit Human	View/Edit Mouse

Equilibrative nucleoside transporter 3 (ENT3) is a protein that in humans is encoded by the gene SLC29A3. As a equilibrative nucleoside transporter, this protein functions to transport nucleosides and similar molecules, with ENT3 specifically transporting across the membranes of the lysosomes and mitochondria. This protein plays multiple important roles including regulating macrophages, participates in urate disposal, and it may also play a part in nucleic acid salvage pathways.

Function

This protein is a uniporter which is capable of transporting a wide variety of molecules, including many nucleosides, deoxynucleosides, nucleobases, ATP, urate, and monoamine neurotransmitters. Unlike its relatives ENT1 (SLC29A1) and ENT2 (SLC29A2) which are primarily found in the cell membrane, ENT3 has only been found their in specific placental cells outside of disease states. Instead, ENT3 is primarily located in membranes of the lysosomes, mitochondria, and (late) endosomes, and its activity is enhanced by low pH.

The role of ENT3 hasn't been as well characterized as ENT1 and ENT2, but it seems to play a role in a number of different pathways.

It can also export urate out of the lysomes, playing a part in (intracellular) disposal, and regulating inflammasome protein activation.
By transporting nucleosides from the lysosomes to the cytosol and the cytosol to the mitochondria, ENT3 may help facilitate nucleic acid salvage.
By exporting nucleosides out of the lysosomes of macrophages, it may play a role in regulating macrophage proliferation and behavior.

Knock-out mice display an excessive numbers of macrophages in their tissue (histiocytosis), and a build-up of nucleosides in the lysosomes. By age 8 weeks, their lymph nodes and spleens grew abnormally large, and they died younger than their littermates.

Medical Significance

Pathogenic mutations in SLC29A3 have been associated with a number of disorders involving dysfunctional tissue macrophages (histiocytosis) that were previous thought to be distinct, now designated under the umbrella term histiocytosis-lymphadenopathy plus syndrome. This is inherited in a autosomal recessive manner, and its most consistent signs across subtypes are histologic features.

References

1 2 3 GRCh38: Ensembl release 89: ENSG00000198246 – Ensembl, May 2017
1 2 3 GRCm38: Ensembl release 89: ENSMUSG00000020100 – Ensembl, May 2017
↑ "Human PubMed Reference:". National Center for Biotechnology Information, U.S. National Library of Medicine.
↑ "Mouse PubMed Reference:". National Center for Biotechnology Information, U.S. National Library of Medicine.
1 2 3 4 5 6 7 8 9 "Equilibrative nucleoside transporter 3". uniprot.org. UniProt consortium. Retrieved 2026-10-26.
1 2 3 4 5 Boswell-Casteel RC, Hays FA (2017-01-02). "Equilibrative nucleoside transporters—A review" (PDF). Nucleosides, Nucleotides and Nucleic Acids. 36 (1): 7–30. doi:10.1080/15257770.2016.1210805.
1 2 McKusick VA, Vernon HJ (2024-04-25). "HISTIOCYTOSIS-LYMPHADENOPATHY PLUS SYNDROME". OMIM. Johns Hopkins university. Retrieved 2026-10-26.

This article on a gene on human chromosome 10 is a stub. You can help Wikipedia by adding missing information.

[refGRCh38Ensembl-1] 1 2 3 GRCh38: Ensembl release 89: ENSG00000198246 – Ensembl, May 2017

[refGRCm38Ensembl-2] 1 2 3 GRCm38: Ensembl release 89: ENSMUSG00000020100 – Ensembl, May 2017

[3] "Human PubMed Reference:". National Center for Biotechnology Information, U.S. National Library of Medicine.

[4] "Mouse PubMed Reference:". National Center for Biotechnology Information, U.S. National Library of Medicine.

[uniprot-5] 1 2 3 4 5 6 7 8 9 "Equilibrative nucleoside transporter 3". uniprot.org. UniProt consortium. Retrieved 2026-10-26.

[BoswellCasteel2017-6] 1 2 3 4 5 Boswell-Casteel RC, Hays FA (2017-01-02). "Equilibrative nucleoside transporters—A review" (PDF). Nucleosides, Nucleotides and Nucleic Acids. 36 (1): 7–30. doi:10.1080/15257770.2016.1210805.

[omim-7] 1 2 McKusick VA, Vernon HJ (2024-04-25). "HISTIOCYTOSIS-LYMPHADENOPATHY PLUS SYNDROME". OMIM. Johns Hopkins university. Retrieved 2026-10-26.