SLC17A5
Solute Carrier Family 17 Member 5
Gene Information Card
| Symbol | SLC17A5 |
|---|---|
| Full Name | Solute Carrier Family 17 Member 5 |
| Gene Type | Protein coding |
| Chromosomal Location | 6q13 |
| NCBI Gene ID | 26503 ncbi.nlm.nih.gov/gene/26503 |
| Ensembl ID | ENSG00000119899 |
| UniProt ID | Q9NRA2 |
| OMIM ID | 604322 |
| HGNC ID | 10933 |
| Aliases | AST, SIALIN, SD, SLD, NSF, ISSD |
Description
SLC17A5 encodes sialin, a lysosomal membrane transporter that exports free sialic acid (N-acetylneuraminic acid) from lysosomes. Defects in this gene lead to accumulation of free sialic acid in lysosomes, causing Salla disease and infantile free sialic acid storage disorder (ISSD). Sialin also transports other anions such as glutamate and aspartate.
Disease Associations
| Disease category | Pathophysiological mechanism | Genomic evidence |
|---|---|---|
| Salla disease | Loss-of-function mutations in SLC17A5 impair sialic acid export from lysosomes, leading to lysosomal storage of free sialic acid and progressive neurodegeneration. | OMIM #604369, ClinVar |
| Infantile free sialic acid storage disorder (ISSD) | Severe loss-of-function mutations (e.g., nonsense, frameshift) cause complete loss of sialin activity, resulting in severe developmental delay, coarse facies, and early death. | OMIM #269920, ClinVar |
| Sialuria (French type) | Dominant gain-of-function mutations in the allosteric site of sialin lead to increased sialic acid transport and urinary excretion. | OMIM #269921 |
Expression Profile
Tissue Expression
| Tissue | nTPM | level |
|---|---|---|
| Brain | 12.5 | Medium |
| Liver | 8.3 | Low |
| Kidney | 10.1 | Medium |
| Lung | 6.7 | Low |
| Placenta | 9.4 | Medium |
Cell Line Expression
| Cell Line | nTPM | Notes |
|---|---|---|
| SH-SY5Y (neuroblastoma) | 14.2 | High expression |
| HepG2 (hepatocellular carcinoma) | 7.8 | Medium expression |
| A549 (lung carcinoma) | 5.3 | Low expression |
Data source：Human Protein Atlas（proteinatlas.org）
Mutations & Variants
Hotspot Mutations
| Variant | Type | Frequency | Functional Description |
|---|---|---|---|
| c.115C>T (p.Arg39Cys) | Missense | Common in Salla disease (Finnish founder) | Impaired sialic acid transport |
| c.100C>T (p.Arg34Ter) | Nonsense | Rare, severe ISSD | Complete loss of function |
| c.746G>A (p.Arg249His) | Missense | Rare, Salla disease | Partial loss of function |
Mutation functional classification
Loss of Function (LOF)
Most SLC17A5 mutations (missense, nonsense, frameshift) reduce or abolish sialin-mediated sialic acid export from lysosomes, causing lysosomal storage disorders.
Gain of Function (GOF)
Dominant mutations (e.g., p.Arg39Cys in sialuria) increase sialic acid transport activity, leading to urinary sialic acid excretion.
Dominant Negative (DN)
Not reported for SLC17A5.
View complete mutation data：
Gene Ontology (GO)
| • high-affinity L-glutamate transmembrane transporter activity (GO:0005314) | • amino acid transmembrane transporter activity (GO:0015171) |
| • symporter activity (GO:0015293) | • antiporter activity (GO:0015297) |
| • lysosome (GO:0005764) | • integral component of membrane (GO:0016021) |
| • transport (GO:0006810) | • polyamine transport (GO:0015846) |
Pathways
• Lysosomal transport (Reactome: R-HSA-432722)
• Sialic acid metabolism (KEGG: hsa00520)
• Amino acid transport across the lysosomal membrane
Protein Summary
Sialin (UniProt Q9NRA2) is a 495-amino acid multi-pass membrane protein localized to the lysosomal membrane. It functions as a proton-coupled symporter that exports free sialic acid and other anions (e.g., glutamate, aspartate) from lysosomes. The protein contains 12 transmembrane domains and is essential for preventing lysosomal storage of sialic acid. Mutations in SLC17A5 cause autosomal recessive Salla disease and ISSD, as well as dominant sialuria.
Related Services
Related Products
| Product name | Cat.No. | Species | Gene ID | |
|---|---|---|---|---|
| SLC17A5 Knockout HEK293 Cell Line | EDJ-KQ2897 | Human | 26503 | Details Get a Quote |
| SLC17A5 Knockout HeLa Cell Line | EDJ-KQ18189 | Human | 26503 | Details Get a Quote |
| SLC17A5 Knockout A-549 Cell Line | EDJ-KQ23972 | Human | 26503 | Details Get a Quote |
| SLC17A5 Knockout HCT 116 Cell Line | EDJ-KQ23973 | Human | 26503 | Details Get a Quote |
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