Targeting of recombinant Na+/glucose cotransporter (SGLT1) to the apical membrane.
A full-length Na+/glucose cotransporter cDNA (SGLT1) from rabbit intestine was subcloned into the pMAMneo mammalian expression vector and transfected by Ca2+ precipitation into Madin-Darby canine kidney (MDCK) cells. Stable MDCK transfectants isolated after clonal isolation and selection in G418 exhibited dexamethasone-inducible Na+/glucose cotransport activity under regulation of the MMTV promoter of the vector. Transfectants expressed the recombinant 75 kDa Na+/glucose cotransporter subunit as shown by Western blot, and SGLT1 mRNA as shown by Northern blot, but these were undetectable in untransfected MDCK cells. Over 93% of total recombinant transport activity was targeted to the apical membrane. This indicates that the primary amino acid sequence of SGLT1 contains the information necessary to target this transporter to the apical membrane.
Kong
C T
CT
Department of Biochemistry and Molecular Biology, University of Texas Medical School, Houston 77225.
Varde
A
A
Lever
J E
JE
D000818:Animals; D001692:Biological Transport; D015152:Blotting, Northern; D015153:Blotting, Western; D002460:Cell Line; D004285:Dogs; D008565:Membrane Proteins / Q000378:metabolism*; D009004:Monosaccharide Transport Proteins / Q000378:metabolism*; D011817:Rabbits; D011994:Recombinant Proteins / Q000378:metabolism; D014162:Transfection
D008565:Membrane Proteins; D009004:Monosaccharide Transport Proteins; D011994:Recombinant Proteins