The apical localization of SGLT1 glucose transporter is determined by the short amino acid sequence in its N-terminal domain

doi:10.1078/0171-9335-00204

European Journal of Cell Biology

Volume 80, Issue 12, December 2001, Pages 765-774

https://doi.org/10.1078/0171-9335-00204 Get rights and content

Summary

SGLT1, an isoform of Na⁺-dependent glucose cotransporters, is localized at the apical plasma membrane in the epithelial cells of the small intestine and the kidney, where it plays a pivotal role in the absorption and reabsorption of sugars, respectively. To search the domain responsible for the apical localization of SGLT1, we constructed an N-terminal deletion clone series of rat SGLT1 and analyzed the localization of the respective products in Madin-Darby canine kidney (MDCK) cells. The products of N-terminal deletion clones up to the 19th amino acid were localized at the apical plasma membrane, whereas the products of N-terminal 20- and 23-amino-acid deletion clones were localized along the entire plasma membrane. Since single-amino-acid mutations of either D28N or D28G in the N-terminal domain give rise to glucose/galactose malabsorption disease, we examined the localization of these mutants. The products of D28N and D28G clones were localized in the cytoplasm, showing that the aspartic acid-28 may be essential for the delivery of SGLT1 to the plasma membrane. These results suggest that a short amino acid sequence of the N-terminal domain of SGLT1 plays important roles in plasma membrane targeting and specific apical localization of the protein.

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The apical localization of SGLT1 glucose transporter is determined by the short amino acid sequence in its N-terminal domain

Summary

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Trends Cell Biol.

Biochim. Biophys. Acta.

Interspecies diversity of the occludin sequence: cDNA cloning of human, mouse, dog, and rat-kangaroo homologues

J. Cell Biol.

Molecular bases for the recognition of tyrosine-based sorting signals

J. Cell Biol.

The cytoplasmic tail of rhodopsin acts as a novel apical sorting signal in polarized MDCK cells

J. Cell Biol.

VIP36, a novel component of glycolipid rafts and exocytic carrier vesicles in epithelial cells

EMBO J.

Characterization of VIP36, an animal lectin homologous to leguminous lectins

J. Cell Sci.

Occludin: a novel integral membrane protein localizing at tight junctions

J. Cell Biol.

Carbohydrate-mediated Golgi to cell surface transport and apical targeting of membrane proteins

EMBO J.

Molecular physiology of sodiumglucose cotransporters

Physiol. Rev.

Cytoplasmic determinants involved in direct lysosomal sorting, endocytosis, and basolateral targeting of rat lgp120 (lamp-I) in MDCK cells

J. Cell Biol.

Post-Golgi biosynthetic trafficking

J. Cell Sci.

Function and presumed molecular structure of Na+-D-glucose cotransport systems

J. Membr. Biol.

Function and presumed molecular structure of Na⁺-D-glucose cotransport systems