A vesicular transporter that mediates aspartate and glutamate neurotransmission.
Aspartate, an excitatory amino acid, is known to be stored in synaptic vesicles and exocytosed from some neurons to perform aspartergic neurotransmission. Through in vitro reconstitution, we found that sialin, a lysosomal sialic acid exporter, is responsible for the vesicular storage of aspartate in hippocampal neurons and pinealocytes. Mutations found in Salla disease cause decreased aspartate transport activity without affecting sialic acid transport. Thus, sialin is a multifunctional transporter. It is possible that people with Salla disease lose the ability of aspartergic neurotransmission, and this could explain why Salla disease involves severe neurological defects.
Department of Genomics and Proteomics, Advanced Science Research Center, Okayama University, Okayama 700–8530, Japan.
Takaaki
T
Miyaji
Hiroshi
H
Omote
Yoshinori
Y
Moriyama
D000818:Animals; D001224:Aspartic Acid / Q000378:metabolism*; D001692:Biological Transport / Q000235:genetics; D018698:Glutamic Acid / Q000378:metabolism*; D006624:Hippocampus / Q000502:physiology*; D006801:Humans; D009154:Mutation; D019158:N-Acetylneuraminic Acid / Q000235:genetics / Q000378:metabolism*; D027361:Organic Anion Transporters / Q000302:isolation & purification / Q000378:metabolism*; D010870:Pineal Gland / Q000502:physiology; D029461:Sialic Acid Storage Disease / Q000235:genetics / Q000378:metabolism* / Q000503:physiopathology; D009435:Synaptic Transmission / Q000235:genetics / Q000502:physiology*; D013572:Synaptic Vesicles / Q000502:physiology
D027361:Organic Anion Transporters; D001224:Aspartic Acid; D018698:Glutamic Acid; D019158:N-Acetylneuraminic Acid