The
glucose transporter family
proteins play pivotal roles in
glucose metabolism. In this study, we successfully cloned the orange spotted grouper (Epinephelus coioides)
glucose transporter 1 (EcGlut1) gene (GenBank accession: JQ623903). The full-length EcGlut1
cDNA was 2126 bp with a 1476 bp ORF, a 437bp5'-UTR and 223bp3'-UTR. EcGlut1 is predicted to encode a 491
amino acid protein with a MW of 53.9 kDa, a pI of 8.66 and a Pfam domain. Bioinformatics analysis revealed that EcGlut1 was evolutionally conserved between fishes with 80-89 %
amino acid identities. EcGlut1 was expressed predominantly in heart and liver and at lower levels in muscle, intestine, stomach and brain. We also investigated the effect of acute
hyperglycemia stress on EcGlut1 expression. In
glucose tolerance test, changes in EcGlut1
mRNA expression in response to
glucose injection and
glucose metabolism-related indictors were assessed at the same time.
Glucose injection significantly suppressed EcGlut1
mRNA expression in liver at 12 h and in brain at 24 h postinjection (P < 0.05). EcGlut1
mRNA levels in heart were increased at 6 h (P < 0.05). Plasma
glucose level increased significantly and reached its maximum at 3 h postinjection (P < 0.05). The spatiotemporal expression of EcGlut1 and
glucose metabolism suggested that orange spotted grouper might rely on fat anabolism to reduce acute
hyperglycemia stress and the delayed transcription of EcGlut1 gene might be one reason for
glucose intolerance in E. coioides.