|PROSITE documentation PDOC00190|
In mammalian cells the uptake of glucose is mediated by a family of closely related transport proteins which are called the glucose transporters [1,2,3]. At least seven of these transporters are currently known to exist (in Human they are encoded by the GLUT1 to GLUT7 genes).
These integral membrane proteins are predicted to comprise twelve membrane spanning domains. The glucose transporters show sequence similarities [4,5] with a number of other sugar or metabolite transport proteins listed below (references are only provided for recently determined sequences).
It has been suggested  that these transport proteins have evolved from the duplication of an ancestral protein with six transmembrane regions, this hypothesis is based on the conservation of two G-R-[KR] motifs. The first one is located between the second and third transmembrane domains and the second one between transmembrane domains 8 and 9.
We have developed two patterns to detect this family of proteins. The first pattern is based on the G-R-[KR] motif; but because this motif is too short to be specific to this family of proteins, we have derived a pattern from a larger region centered on the second copy of this motif. The second pattern is based on a number of conserved residues which are located at the end of the fourth transmembrane segment and in the short loop region between the fourth and fifth segments.Last update:
April 2006 / Patterns revised.
PROSITE methods (with tools and information) covered by this documentation:
|Title||Structure and function of hexose transporters.|
|Source||Annu. Rev. Biochem. 60:757-794(1991).|
|2||Authors||Gould G.W. Bell G.I.|
|Title||Facilitative glucose transporters: an expanding family.|
|Source||Trends Biochem. Sci. 15:18-23(1990).|
|Title||Mammalian passive glucose transporters: members of an ubiquitous family of active and passive transport proteins.|
|Source||Biochim. Biophys. Acta 1154:17-49(1993).|
|4||Authors||Maiden M.C.J. Davis E.O. Baldwin S.A. Moore D.C.M. Henderson P.J.F.|
|Title||Mammalian and bacterial sugar transport proteins are homologous.|
|Source||Curr. Opin. Struct. Biol. 1:590-601(1991).|
|6||Authors||Culham D.E. Lasby B. Marangoni A.G. Milner J.L. Steer B.A. van Nues R.W. Wood J.M.|
|Title||Isolation and sequencing of Escherichia coli gene proP reveals unusual structural features of the osmoregulatory proline/betaine transporter, ProP.|
|Source||J. Mol. Biol. 229:268-276(1993).|