Do rodents have a gene encoding glycogenin-2, the liver isoform of the self-glucosylating initiator of glycogen synthesis?
The discovery of a second human gene, GYG2, encoding a liver-specific isoform of glycogenin, the self-glucosylating initiator of glycogen biosynthesis, raised the possibility for differential controls of this protein in liver and muscle. The new protein, glycogenin-2, had several properties similar biochemically to the muscle isoform, glycogenin-1, but unlike glycogenin-1, stable expression in fibroblasts led to a significant overaccumulation of glycogen. Ensuing attempts to generate reagents suitable for use with rodents, to examine the physiological regulation of glycogenin-2 by nutritional and hormonal factors, have been unsuccessful. Proof of a negative is difficult but the weight of the evidence is beginning to mitigate against the existence of a second glycogenin gene in rodents leading us to hypothesize that the presence of the GYG2 gene is limited to primates.
Zhai
L
L
Department of Biochemistry and Molecular Biology, and Center for Diabetes Research, Indiana University School of Medicine, Indianapolis 46202, USA.
Schroeder
J
J
Skurat
A V
AV
Roach
P J
PJ
D000818:Animals; D001483:Base Sequence; D017931:DNA Primers; D005964:Glucosyltransferases; D006003:Glycogen / Q000096:biosynthesis*; D006023:Glycoproteins / Q000235:genetics* / Q000378:metabolism; D006801:Humans; D008099:Liver / Q000378:metabolism*; D020033:Protein Isoforms / Q000235:genetics* / Q000378:metabolism; D012377:Rodentia
D017931:DNA Primers; D006023:Glycoproteins; D020033:Protein Isoforms; D006003:Glycogen; D005964:Glucosyltransferases; C109150:GYG2 protein, human