PUBLICATION

Evolutionary structural and functional conservation of an ortholog of the GLUT2 glucose transporter gene (SLC2A2) in zebrafish

Authors
Castillo, J., Crespo, D., Capilla, E., Diaz, M., Chauvigne, F., Cerdà, J., and Planas, J.V.
ID
ZDB-PUB-090929-6
Date
2009
Source
American journal of physiology. Regulatory, integrative and comparative physiology   297(5): R1570-R1581 (Journal)
Registered Authors
Cerdà, Joan
Keywords
none
MeSH Terms
  • Amino Acid Sequence
  • Animals
  • Evolution, Molecular*
  • Exons/genetics
  • Glucose/metabolism
  • Glucose Transporter Type 2/genetics*
  • Glucose Transporter Type 2/physiology*
  • Humans
  • Intestines/metabolism
  • Introns/genetics
  • Models, Animal
  • Molecular Sequence Data
  • Trout
  • Zebrafish/genetics*
PubMed
19776250 Full text @ Am. J. Physiol. Regul. Integr. Comp. Physiol.
Abstract
In mammals, GLUT2 plays an essential role in glucose homeostasis. From an evolutionary perspective, relatively little is known about the biology of GLUT2, or other GLUTs, in non-mammalian vertebrates. Here, we have conducted studies to functionally characterize GLUT2 in zebrafish. First, we cloned the zebrafish ortholog of GLUT2 (zfGLUT2) encoding a protein of 504 amino acids with high sequence identity to other known vertebrate GLUT2 proteins. The zfGLUT2 gene consists of 11 exons and 10 introns, spanning 20kb and mapping to a region of chromosome 2 that exhibits conserved synteny with human chromosome 3. When expressed in Xenopus oocytes, zfGLUT2 transported 2-deoxyglucose (2-DG) with similar affinity than mammalian GLUT2 (Km of 11 mM). Transport of 2-DG was competed mostly by D-fructose and D-mannose and was inhibited by cytochalasin B. During early development, zfGLUT2 expression was detected already at 10 hours post fertilization and remained elevated in 5-day larvae, when it was clearly localized to the liver and intestinal bulb. In the adult, zfGLUT2 expression was highest in testis, brain, skin, kidney and intestine, followed by liver and muscle. In the intestine, zfGLUT2 transcripts were detected in absorptive enterocytes and its mRNA levels were altered by fasting and refeeding, suggesting that its expression in the intestine may be regulated by the nutritional status. These results indicate that the structure and function of GLUT2 has been remarkably well conserved during vertebrate evolution and open the way for the use of zebrafish as a model species in which to study the biology and pathophysiology of GLUT2. Key words: GLUT2, gene expression, glucose transport, intestine.
Genes / Markers
Figures
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Expression
Phenotype
Mutations / Transgenics
Human Disease / Model
Sequence Targeting Reagents
Fish
Antibodies
Orthology
Engineered Foreign Genes
Mapping