SLC6A19: The Neutral Amino Acid Transporter B0AT1 in Hartnup Disorder and Metabolic Health
Explore the SLC6A19 gene, its role in amino acid transport, associated diseases like Hartnup disorder, tissue expression, mutations, and clinical significance.
Gene Information Card
| Symbol | SLC6A19 |
|---|---|
| Full Name | Solute carrier family 6 member 19 |
| Gene Type | protein coding |
| Chromosomal Location | 5p15.33 |
| NCBI Gene ID | 285335 ncbi.nlm.nih.gov/gene/285335 |
| Ensembl ID | ENSG00000174358 |
| UniProt ID | Q9HBR0 |
| OMIM ID | 608893 |
| HGNC ID | 27961 |
| Aliases | B0AT1, HND, FLJ20644 |
Description
SLC6A19 encodes a sodium-dependent neutral amino acid transporter, known as B0AT1, primarily expressed in the kidney proximal tubule and small intestine. It mediates the uptake of neutral amino acids across the apical membrane, playing a critical role in amino acid homeostasis. Mutations in SLC6A19 cause Hartnup disorder, an autosomal recessive condition characterized by aminoaciduria and potential neurological symptoms. The transporter is also implicated in metabolic regulation and is a target for therapeutic intervention in amino acid metabolism disorders.
Disease Associations
| Disease category | Pathophysiological mechanism | Genomic evidence |
|---|---|---|
| Hartnup disorder | Loss-of-function mutations in SLC6A19 impair neutral amino acid reabsorption in the kidney and intestine, leading to excessive urinary excretion and deficiency of tryptophan and other amino acids. | OMIM 234500; ClinVar; multiple pathogenic variants documented. |
| Hypertension (possible modifier) | SLC6A19 variants may influence blood pressure through altered amino acid metabolism, though evidence is preliminary. | GWAS studies; not yet clinically validated. |
Expression Profile
Tissue Expression
| Tissue | nTPM | level |
|---|---|---|
| Kidney | High (nTPM ~ 50) | Predominant expression in proximal tubule |
| Small intestine | High (nTPM ~ 40) | Apical membrane of enterocytes |
| Liver | Low (nTPM ~ 5) | Minimal expression |
| Pancreas | Low (nTPM ~ 3) | Not significant |
Cell Line Expression
| Cell Line | nTPM | Notes |
|---|---|---|
| HK-2 (kidney proximal tubule) | High | Model for renal amino acid transport |
| Caco-2 (intestinal epithelial) | High | Used for intestinal absorption studies |
| HepG2 (liver) | Low | Not a primary site |
Data source：Human Protein Atlas（proteinatlas.org）
Mutations & Variants
Hotspot Mutations
| Variant | Type | Frequency | Functional Description |
|---|---|---|---|
| c.850G>A (p.Gly284Arg) | Missense | Rare (MAF < 0.01) | Loss of function; associated with Hartnup disorder |
| c.1040C>T (p.Thr347Met) | Missense | Rare | Loss of function; reduced transport activity |
| c.1225C>T (p.Arg409Ter) | Nonsense | Rare | Truncated protein; loss of function |
| c.1280delA (p.Lys427SerfsTer) | Frameshift | Rare | Loss of function; premature stop |
Mutation functional classification
Loss of Function (LOF)
Most pathogenic mutations lead to loss of transporter function, reducing amino acid reabsorption and causing Hartnup disorder.
Gain of Function (GOF)
No gain-of-function mutations have been reported for SLC6A19.
Dominant Negative (DN)
No dominant-negative effects documented; disorder is autosomal recessive.
View complete mutation data：
Gene Ontology (GO)
| • amino acid transmembrane transporter activity | • sodium ion binding |
| • neutral amino acid transport | • plasma membrane |
| • apical plasma membrane | • response to amino acid starvation |
Pathways
• Amino acid transport across the apical membrane
• Tryptophan metabolism (via substrate availability)
• Sodium-coupled amino acid transport
Protein Summary
The SLC6A19 protein (B0AT1) is a 634-amino acid transmembrane protein with 12 predicted transmembrane domains. It functions as a sodium-dependent symporter for neutral amino acids, including tryptophan, phenylalanine, and leucine. It requires the accessory protein collectrin (TMEM27) for surface expression in the kidney. The protein is critical for amino acid homeostasis; defects lead to Hartnup disorder. Structural studies suggest a conserved LeuT-fold architecture typical of the SLC6 family.
Related Services
Related Products
| Product name | Cat.No. | Species | Gene ID | |
|---|---|---|---|---|
| SLC6A19 Knockout HEK293 Cell Line | EDJ-KQ15285 | Human | 340024 | Details Get a Quote |
| SLC6A19 Knockout HeLa Cell Line | EDJ-KQ59662 | Human | 340024 | Details Get a Quote |
| SLC6A19 Knockout A-549 Cell Line | EDJ-KQ68133 | Human | 340024 | Details Get a Quote |
| SLC6A19 Knockout HCT 116 Cell Line | EDJ-KQ76509 | Human | 340024 | Details Get a Quote |
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