Identification of a mammalian H(+)-myo-inositol symporter expressed predominantly in the brain.

Détails

ID Serval
serval:BIB_8DEEB384CFF5
Type
Article: article d'un périodique ou d'un magazine.
Collection
Publications
Institution
Titre
Identification of a mammalian H(+)-myo-inositol symporter expressed predominantly in the brain.
Périodique
EMBO journal
Auteur(s)
Uldry M., Ibberson M., Horisberger J.D., Chatton J.Y., Riederer B.M., Thorens B.
ISSN
0261-4189
Statut éditorial
Publié
Date de publication
08/2001
Peer-reviewed
Oui
Volume
20
Numéro
16
Pages
4467-4477
Langue
anglais
Résumé
Inositol and its phosphorylated derivatives play a major role in brain function, either as osmolytes, second messengers or regulators of vesicle endo- and exocytosis. Here we describe the identification and functional characterization of a novel H(+)-myo- inositol co-transporter, HMIT, expressed predominantly in the brain. HMIT cDNA encodes a 618 amino acid polypeptide with 12 predicted transmembrane domains. Functional expression of HMIT in Xenopus oocytes showed that transport activity was specific for myo-inositol and related stereoisomers with a Michaelis-Menten constant of approximately 100 microM, and that transport activity was strongly stimulated by decreasing pH. Electrophysiological measurements revealed that transport was electrogenic with a maximal transport activity reached at pH 5.0. In rat brain membrane preparations, HMIT appeared as a 75-90 kDa protein that could be converted to a 67 kDa band upon enzymatic deglycosylation. Immunofluorescence microscopy analysis showed HMIT expression in glial cells and some neurons. These data provide the first characterization of a mammalian H(+)-coupled myo- inositol transporter. Predominant central expression of HMIT suggests that it has a key role in the control of myo-inositol brain metabolism.
Mots-clé
Amino Acid Sequence, Animals, Base Sequence, Brain, Cell Line, Transformed, DNA, Complementary, Electrophysiology, Glucose Transport Proteins, Facilitative, Humans, Hydrogen-Ion Concentration, Inositol, Intracellular Fluid, Mammals, Membrane Proteins, Microscopy, Fluorescence, Molecular Sequence Data, Monosaccharide Transport Proteins, RNA, Messenger, Rats, Xenopus
Pubmed
Web of science
Open Access
Oui
Création de la notice
24/01/2008 14:34
Dernière modification de la notice
20/08/2019 14:51
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