Abstract
Human SGLT1 protein is an established sodium-glucose cotransporter. Despite widespread use of the mouse as a model organism, the mouse SGLT1 homologue has yet to be functionally characterized. Additionally, the crystal structure of a sugar transporter homologue, Vibrio SGLT, has recently been described, however, it offers limited information about the role of transmembrane segments outside of the core ligand binding domains. In particular, the amino acids in TM1 were not assigned in the structure. To examine the contribution of TM1 to the function of SGLT1, we have cloned and characterized the biophysical properties of SGLT1 from mouse, mSGLT1, and compared it to a clone containing an amino acid substitution in TM1, F36S. As predicted, both proteins formed functional Na+/sugar cotransporters, but F36S-mSGLT1 showed decreased rates of sugar uptake and decreased apparent affinities for both Na+ and sugar compared to mSGLT1. Analysis of pre-steady-state currents and comparison with the crystal structure of Vibrio SGLT provide plausible mechanisms to explain the differences in function of these two proteins. Our data suggest that amino acids in TM1, which are not involved in ligand binding and translocation pathways, significantly influence the functional properties of sodium-glucose carrier proteins.
This is a preview of subscription content, log in via an institution to check access.
Similar content being viewed by others
References
Birnir B, Loo DD, Wright EM (1991) Voltage-clamp studies of the Na+/glucose cotransporter cloned from rabbit small intestine. Pflugers Arch 418:79–85
Breyer MD, Tchekneva E, Qi Z, Takahashi T, Fogo AB, Harris RC (2007) Examining diabetic nephropathy through the lens of mouse genetics. Curr Diab Rep 7:459–466
Díez-Sampedro A, Lostao MP, Wright EM, Hirayama BA (2000) Glycoside binding and translocation in Na(+)-dependent glucose cotransporters: comparison of SGLT1 and SGLT3. J Membr Biol 176:111–117
Dyer J, Hosie KB, Shirazi-Beechey SP (1997) Nutrient regulation of human intestinal sugar transporter (SGLT1) expression. Gut 41:56–59
Faham S, Watanabe A, Besserer GM, Cascio D, Specht A, Hirayama BA, Wright EM, Abramson J (2008) The crystal structure of a sodium galactose transporter reveals mechanistic insights into Na+/sugar symport. Science 321:810–814
Ferraris RP, Diamond JM (1993) Crypt/villus site of substrate-dependent regulation of mouse intestinal glucose transporters. Proc Natl Acad Sci USA 90:5868–5872
Hardcastle J, Harwood MD, Taylor CJ (2004) Absorption of taurocholic acid by the ileum of normal and transgenic DeltaF508 cystic fibrosis mice. J Pharm Pharmacol 56:445–452
Hirayama BA, Wong HC, Smith CD, Hagenbuch BA, Hediger MA, Wright EM (1991) Intestinal and renal Na+/glucose cotransporters share common structure. Am J Physiol 261:C296–C304
Hirayama BA, Lostao MP, Panayotova-Heiermann M, Loo DD, Turk E, Wright EM (1996) Kinetic and specificity differences between rat, human, and rabbit Na+-glucose cotransporters (SGLT–1). Am J Physiol 270:G919–G926
Ikeda TS, Hwang ES, Coady MJ, Hirayama BA, Hediger MA, Wright EM (1989) Characterization of a Na+/glucose cotransporter cloned from rabbit small intestine. J Membr Biol 110:87–95
Kimmich GA (1981) Intestinal absorption of sugar. In: Johnson LR (ed) Physiology of the gastrointestinal tract. Raven Press, New York
Lam MM, O’Connor TP, Diamond J (2002) Loads, capacities and safety factors of maltase and the glucose transporter SGLT1 in mouse intestinal brush border. J Physiol 542:493–500
Lescale-Matys L, Dyer J, Scott D, Freeman TC, Wright EM, Shirazi-Beechey SP (1993) Regulation of the ovine intestinal Na +/glucose co-transporter (SGLT1) is dissociated from mRNA abundance. Biochem J 291:435–440
Loo DD, Hazama A, Supplisson S, Turk E, Wright EM (1993) Relaxation kinetics of the Na+/glucose cotransporter. Proc Natl Acad Sci USA 90:5767–5771
Loo DD, Hirayama BA, Gallardo EM, Lam JT, Turk E, Wright EM (1998) Conformational changes couple Na+ and glucose transport. Proc Natl Acad Sci USA 95:7789–7794
Loo DD, Hirayama BA, Karakossian MH, Meinild AK, Wright EM (2006) Conformational dynamics of hSGLT1 during Na+/glucose cotransport. J Gen Physiol 128:701–720
Lostao MP, Hirayama BA, Loo DD, Wright EM (1994) Phenylglucosides and the Na+/glucose cotransporter (SGLT1): analysis of interactions. J Membr Biol 142:161–170
Panayotova-Heiermann M, Loo DD, Lostao MP, Wright EM (1994) Sodium/D-glucose cotransporter charge movements involve polar residues. J Biol Chem 269:21016–21020
Panayotova-Heiermann M, Loo DD, Wright EM (1995) Kinetics of steady-state currents and charge movements associated with the rat Na+/glucose cotransporter. J Biol Chem 270:27099–27105
Parent L, Supplisson S, Loo DD, Wright EM (1992) Electrogenic properties of the cloned Na+/glucose cotransporter. I. Voltage-clamp studies. J Membr Biol 125:49–62
Sandu C, Rexhepaj R, Grahammer F, McCormick JA, Henke G, Palmada M, Nammi S, Lang U, Metzger M, Just L, Skutella T, Dawson K, Wang J, Pearce D, Lang F (2005) Decreased intestinal glucose transport in the sgk3-knockout mouse. Pflugers Arch 451:437–444
Shirazi-Beechey SP, Hirayama BA, Wang Y, Scott D, Smith MW, Wright EM (1991) Ontogenic development of lamb intestinal sodium-glucose co-transporter is regulated by diet. J Physiol 437:699–708
Solberg DH, Diamond JM (1987) Comparison of different dietary sugars as inducers of intestinal sugar transporters. Am J Physiol 252:G574–G584
Tabatabai NM, Blumenthal SS, Lewand DL, Petering DH (2001) Differential regulation of mouse kidney sodium-dependent transporters mRNA by cadmium. Toxicol Appl Pharmacol 177:163–173
Yamashita A, Singh SK, Kawate T, Jin Y, Gouaux E (2005) Crystal structure of a bacterial homologue of Na+/Cl− dependent neurotransmitter transporters. Nature 437:215–223
Acknowledgments
I thank Rebekah Denison for technical assistance and E. M. Wright, B. A. Hirayama, D. D. Loo, C. Grewer, and P. Larsson for comments and suggestions on the manuscript.
Author information
Authors and Affiliations
Corresponding author
Rights and permissions
About this article
Cite this article
Díez-Sampedro, A. Involvement of Amino Acid 36 in TM1 in Voltage Sensitivity in Mouse Na+/Glucose Cotransporter SGLT1. J Membrane Biol 227, 57–66 (2009). https://doi.org/10.1007/s00232-008-9143-3
Received:
Accepted:
Published:
Issue Date:
DOI: https://doi.org/10.1007/s00232-008-9143-3