Figure 9. Nuclear localization of glycogen synthase does not require the presence of a basic region at the C-terminus, implicated in glucose-6-P binding.
The yeast strain CC9, which lacks both isoforms of glycogenin, was transformed with a construct encoding a R579A/R580A/R582A mutant of Gsy2-GFP (pWW220). This region had been implicated in binding glucose-6-P and also in the nuclear uptake of mammalian muscle glycogen synthase. The subcellular distribution of the R579A/R580A/R582A mutant was determined after overnight growth in SC-Trp medium. DNA was stained using Hoechst 33342 dye. The R579A/R580A/R582A mutant was found in the nucleus. The scale bar represents 10 μm.