Slc17A5 Protein is an important component in the neurobiology of neurodegenerative diseases. This page provides detailed information about its structure, function, and role in disease processes.
| SLC17A5 Protein | |
|---|---|
| Protein Name | Sialin (Sialic acid transporter) |
| Gene | SLC17A5 |
| UniProt ID | Q9NRX3 |
| Chromosomal Location | 6q13 |
| Description | Lysosomal sialic acid transporter involved in sialidosis and neurodegeneration |
| Subcellular Localization | Lysosome, plasma membrane |
| Protein Family | Solute Carrier Family 17 (SLC17) |
Sialin (SLC17A5) is a lysosomal membrane protein that functions as a sialic acid transporter and anion channel. It plays crucial roles in lysosomal homeostasis, neurotransmitter recycling, and cellular glycobiology. Mutations in the SLC17A5 gene cause sialidosis and infantile sialic acid storage disease (ISSD), while dysregulation is implicated in Alzheimer's disease, Parkinson's disease, and various metabolic disorders.
Sialin is a polytopic membrane protein with 10-12 predicted transmembrane domains. The protein contains:
The protein functions as a symporter, using the proton gradient to drive sialic acid export from lysosomes.
Sialin is primarily responsible for exporting sialic acid (N-acetylneuraminic acid) from lysosomes into the cytoplasm. This function is essential for:
In neurons and glial cells, sialin participates in:
Sialin maintains lysosomal homeostasis through:
Sialin dysfunction contributes to AD pathogenesis through multiple mechanisms:
Amyloid precursor protein processing: Altered sialylation affects APP processing and amyloid-beta generation[1]
Lysosomal dysfunction: Impaired sialic acid export leads to lysosomal stress and impaired autophagic flux
Neuroinflammation: Dysregulated sialic acid metabolism modulates microglial activation and inflammatory responses
Tau pathology: Altered glycoprotein sialylation may affect tau phosphorylation and aggregation
In Parkinson's disease, sialin plays important roles:
Dopamine neuron vulnerability: Sialin expression in substantia nigra dopaminergic neurons makes them susceptible to dysfunction
Alpha-synuclein sialylation: Altered sialic acid metabolism affects alpha-synuclein post-translational modifications and aggregation propensity[2]
Lysosomal dysfunction: Impaired sialin function contributes to general lysosomal impairment observed in PD
SLC17A5 mutations cause two related disorders:
These disorders result from accumulation of sialic acid in lysosomes due to defective export.
Targeting sialin function offers therapeutic potential:
The study of Slc17A5 Protein has evolved significantly over the past decades. Research in this area has revealed important insights into the underlying mechanisms of neurodegeneration and continues to drive therapeutic development.
Historical context and key discoveries in this field have shaped our current understanding and will continue to guide future research directions.