GALE cDNA Clone – UDP-Galactose-4-Epimerase (Human)

This gene encodes UDP-galactose-4-epimerase which catalyzes two distinct but analogous reactions: the epimerization of UDP-glucose to UDP-galactose, and the epimerization of UDP-N-acetylglucosamine to UDP-N-acetylgalactosamine. The bifunctional nature of the enzyme has the important metabolic consequence that mutant cells (or individuals) are dependent not only on exogenous galactose, but also on exogenous N-acetylgalactosamine as a necessary precursor for the synthesis of glycoproteins and glycolipids. Mutations in this gene result in epimerase-deficiency galactosemia, also referred to as galactosemia type 3, a disease characterized by liver damage, early-onset cataracts, deafness and mental retardation, with symptoms ranging from mild ('peripheral' form) to severe ('generalized' form). Multiple alternatively spliced transcripts encoding the same protein have been identified. [provided by RefSeq, Jul 2008]

GALE: Catalyzes two distinct but analogous reactions: the epimerization of UDP-glucose to UDP-galactose and the epimerization of UDP-N-acetylglucosamine to UDP-N- acetylgalactosamine. Defects in GALE are the cause of epimerase-deficiency galactosemia (EDG); also known as galactosemia type 3. Clinical features include early-onset cataracts, liver damage, deafness and mental retardation. There are two clinically distinct forms of EDG. (1) A benign, or 'peripheral' form with no detectable GALE activity in red blood cells and characterized by mild symptoms. Some patients may suffer no symptoms beyond raised levels of galactose-1-phosphate in the blood. (2) A much rarer 'generalized' form with undetectable levels of GALE activity in all tissues and resulting in severe features such as restricted growth and mental development. Belongs to the sugar epimerase family.

Protein type: Carbohydrate Metabolism - amino sugar and nucleotide sugar; EC 5.1.3.2; Carbohydrate Metabolism - galactose; Isomerase; EC 5.1.3.7

Chromosomal Location of Human Ortholog: 1p36-p35

Cellular Component: cytosol

Molecular Function: protein homodimerization activity; UDP-glucose 4-epimerase activity

Biological Process: galactose catabolic process

Disease: Galactose Epimerase Deficiency