SLC17A5
Developmental stage
Found in fetal lung and small intestine, and at lower level in fetal skin and muscle.
Function
Multifunctional anion transporter that operates via two distinct transport mechanisms, namely proton-coupled anion cotransport and membrane potential-dependent anion transport (PubMed:15510212, PubMed:21781115, PubMed:22778404, PubMed:23889254). Electroneutral proton-coupled acidic monosaccharide symporter, with a sugar to proton stoichiometry of 1:1. Exports glucuronic acid and free sialic acid derived from sialoglycoconjugate degradation out of lysosomes, driven by outwardly directed lysosomal pH gradient. May regulate lysosome function and metabolism of sialylated conjugates that impact oligodendrocyte lineage differentiation and myelinogenesis in the central nervous system (By similarity) (PubMed:15510212, PubMed:21781115, PubMed:22778404, PubMed:23889254). Electrogenic proton-coupled nitrate symporter that transports nitrate ions across the basolateral membrane of salivary gland acinar cells, with nitrate to proton stoichiometry of 2:1. May contribute to nitrate clearance from serum by salivary glands, where it is further concentrated and secreted in the saliva (PubMed:22778404). Uses membrane potential to drive the uptake of acidic amino acids and peptides into synaptic vesicles. Responsible for synaptic vesicular storage of L-aspartate and L-glutamate in pinealocytes as well as vesicular uptake of N-acetyl-L-aspartyl-L-glutamate neuropeptide, relevant to aspartegic-associated glutamatergic neurotransmission and activation of metabotropic receptors that inhibit subsequent transmitter release (By similarity) (PubMed:21781115, PubMed:22778404, PubMed:23889254).
Receptor for CM101, a polysaccharide produced by group B Streptococcus with antipathoangiogenic properties.
Involvement in disease
Salla disease
SD
Sialic acid storage disease (SASD). SASDs are autosomal recessive neurodegenerative disorders characterized by hypotonia, cerebellar ataxia and intellectual disability. They are caused by a defect in the metabolism of sialic acid which results in increased urinary excretion of unconjugated sialic acid, specifically N-acetylneuraminic acid. Enlarged lysosomes are seen on electron microscopic studies. Clinical symptoms of SD present usually at age less than 1 year and progression is slow.
None
The disease is caused by variants affecting the gene represented in this entry.
Infantile sialic acid storage disorder
ISSD
Severe form of sialic acid storage disease. Affected newborns exhibit visceromegaly, coarse features and failure to thrive immediately after birth. These patients have a shortened life span, usually less than 2 years.
None
The disease is caused by variants affecting the gene represented in this entry.
Sequence Similarities
Belongs to the major facilitator superfamily. Sodium/anion cotransporter family.
Tissue Specificity
In the adult, detected in placenta, kidney and pancreas. Abundant in the endothelial cells of tumors from ovary, colon, breast and lung, but is not detected in endothelial cells from the corresponding normal tissues (PubMed:10581036, PubMed:11751519). Highly expressed in salivary glands and liver, with lower levels of expression in brain, spleen kidney, muscle and pancreas. Expressed in acinar cells of salivary glands (at protein level) (PubMed:22778404).
Cellular localization
- Basolateral cell membrane
- Multi-pass membrane protein
- Cytoplasmic vesicle
- Secretory vesicle
- Synaptic vesicle membrane
- Multi-pass membrane protein
- Lysosome membrane
- Multi-pass membrane protein
Alternative names
Sialin, H(+)/nitrate cotransporter, H(+)/sialic acid cotransporter, Membrane glycoprotein HP59, Solute carrier family 17 member 5, Vesicular excitatory amino acid transporter, AST, VEAT, SLC17A5