E-MEXP-1420 - Transcription profiling of wild type, GALT-deficient and GALT-deficient-revertant yeast grown on media with galactose or glucose
Released on 10 April 2008, last updated on 12 October 2011
To better understand the pathophysiology of galactose-1-phosphate uridyltransferase (GALT) deficiency in humans, we studied the mechanisms by which a GALT-deficient yeast survived on galactose medium. Under normal conditions, GALT-deficient yeast cannot grow in medium that contains 0.2% galactose as the sole carbohydrate, a phenotype of Gal(-). We isolated revertants from a GALT-deficient yeast by direct selection for growth in galactose, a phenotype of Gal(+). Comparison of gene expression profiles among wild-type and revertant strains on galactose medium revealed that the revertant down-regulated genes encoding enzymes including galactokinase, galactose permease, and UDP-galactose-4-epimerase (the GAL regulon). By contrast, the revertant strain up-regulated the gene for UDP-glucose pyrophosphorylase, UGP1. There was reduced accumulation of galactose-1-phosphate in the galactose-grown revertant cells when compared to the GALT-deficient parent cells.
transcription profiling by array, co-expression, growth condition, in vivo
Overexpression of human UDP-glucose pyrophosphorylase rescues galactose-1-phosphate uridyltransferase-deficient yeast PMID 10799308. Lai K; Elsas L.J.