Sequence, tissue distribution, and differential expression of mRNA for a putative insulin-responsive glucose transporter in mouse 3T3-L1 adipocytes.
The cDNAs for two putative glucose transporters from mouse 3T3-L1 adipocytes were isolated and sequenced. One of these cDNAs encodes the murine homolog of the human hepG2/erythrocyte glucose transporter, termed GT1. GT1 mRNA is most abundant in mouse brain and is expressed in both 3T3-L1 preadipocytes and adipocytes. The other cDNA encodes a glucose transporter-like protein, termed GT2, that has a unique amino acid sequence and tissue distribution. GT2 cDNA encodes a protein with 63% amino acid sequence identity and a similar structural organization to GT1. GT2 mRNA is found at high levels in mouse skeletal muscle, heart, and adipose tissue, all of which exhibit insulin-stimulated glucose uptake. GT2 mRNA is absent from 3T3-L1 preadipocytes but is induced dramatically during differentiation into adipocytes. This increase in mRNA content correlates closely with the acquisition of insulin-stimulated glucose uptake. We propose that GT2 is an insulin-regulated glucose transporter.
Kaestner
K H
KH
Department of Biological Chemistry, Johns Hopkins University School of Medicine, Baltimore, MD 21205.
Christy
R J
RJ
McLenithan
J C
JC
Braiterman
L T
LT
Cornelius
P
P
Pekala
P H
PH
Lane
M D
MD
D000273:Adipose Tissue / Q000187:drug effects / Q000378:metabolism*; D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D002454:Cell Differentiation; D002460:Cell Line; D004247:DNA / Q000235:genetics; D005786:Gene Expression Regulation; D005947:Glucose / Q000378:metabolism; D006801:Humans; D007328:Insulin / Q000494:pharmacology*; D051379:Mice; D008969:Molecular Sequence Data; D009004:Monosaccharide Transport Proteins / Q000235:genetics*; D012333:RNA, Messenger / Q000032:analysis / Q000235:genetics*; D012689:Sequence Homology, Nucleic Acid; D014018:Tissue Distribution
D007328:Insulin; D009004:Monosaccharide Transport Proteins; D012333:RNA, Messenger; D004247:DNA; D005947:Glucose