GLUT8 is a glucose transporter responsible for insulin-stimulated glucose uptake in the blastocyst.
Mammalian preimplantation blastocysts exhibit insulin-stimulated glucose uptake despite the absence of the only known insulin-regulated transporter, GLUT4. We describe a previously unidentified member of the mammalian facilitative GLUT superfamily that exhibits approximately 20-25% identity with other murine facilitative GLUTs. Insulin induces a change in the intracellular localization of this protein, which translates into increased glucose uptake into the blastocyst, a process that is inhibited by antisense oligoprobes. Presence of this transporter may be necessary for successful blastocyst development, fuel metabolism, and subsequent implantation. Moreover, the existence of an alternative transporter may explain examples in other tissues of insulin-regulated glucose transport in the absence of GLUT4.
Carayannopoulos
M O
MO
Department of Obstetrics and Gynecology, 4911 Barnes-Jewish Hospital Plaza, St. Louis, MO 63110, USA.
Chi
M M
MM
Cui
Y
Y
Pingsterhaus
J M
JM
McKnight
R A
RA
Mueckler
M
M
Devaskar
S U
SU
Moley
K H
KH
D000595:Amino Acid Sequence; D000818:Animals; D001692:Biological Transport; D001755:Blastocyst / Q000378:metabolism*; D005786:Gene Expression Regulation; D005947:Glucose / Q000378:metabolism*; D051246:Glucose Transport Proteins, Facilitative; D007004:Hypoglycemic Agents / Q000494:pharmacology*; D007328:Insulin / Q000494:pharmacology*; D051379:Mice; D008807:Mice, Inbred BALB C; D008969:Molecular Sequence Data; D009004:Monosaccharide Transport Proteins / Q000235:genetics / Q000378:metabolism*; D020539:Sequence Analysis, Protein
D051246:Glucose Transport Proteins, Facilitative; D007004:Hypoglycemic Agents; D007328:Insulin; D009004:Monosaccharide Transport Proteins; C498628:Slc2a8 protein, mouse; D005947:Glucose