Disorders of galactose metabolism (Homo sapiens)
From WikiPathways
Description
Galactose is converted into glucose 1-phosphate (G1P) through a series of steps called the Leloir pathway. The first step of the pathway is the phosphorylation of galactose by galactokinase (encoded GALK1) to yield galactose 1-phosphate. Conversion of galactose 1-phosphate to G1P requires the transfer of UDP from UDP-glucose catalyzed by GALT. UDP-galactose is converted to UDP-glucose by GALE. Glucose-1-phosphate is converted to glucose-6-phosphate by phosphoglucomutase (PGM) and vice versa.
There are two known disorders concerning the uptake transports of galactose (SGLT1 and GLUT2 deficiency) and three known disorders of galactose metabolism: galactokinase deficiency (GALK-D), galactose 1-phosphate uridyltransferase deficiency (galactosemia, GALT-D) and uridine diphosphate galactose 4-epimerase deficiency (GALE-D).
Among these, galactosemia is the most common and most severe. This pathway was inspired by Chapter 18, figure 18.3 of the book of Blau (4th edition; ISBN: 978-3-642-40337-8).Quality Tags
Ontology Terms
Bibliography
- Dorit Koren, Andrew Palladino; ''Hypoglycemia. Genetic Diagnosis of endocrine disorders''; https://doi.org/10.1016/B978-0-12-800892-8.00003-8, 2016 DOI Scholia
- Coelho AI, Berry GT, Rubio-Gozalbo ME; ''Galactose metabolism and health.''; Curr Opin Clin Nutr Metab Care, 2015 PubMed Europe PMC Scholia
- Morava E; ''Galactose supplementation in phosphoglucomutase-1 deficiency; review and outlook for a novel treatable CDG.''; Mol Genet Metab, 2014 PubMed Europe PMC Scholia
- Blau, Nenad, Duran, Marinus, Gibson, K. Michael, Dionisi-Vici, Carlo.; ''Physician's Guide to the Diagnosis, Treatment, and Follow-Up of Inherited Metabolic Diseases''; Springer-Verlag Berlin Heidelberg, ed.4. 2014. DOI Scholia
History
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External references
DataNodes
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Name | Type | Database reference | Comment |
---|---|---|---|
AKR1B1 | GeneProduct | ENSG00000085662 (Ensembl) | |
D-galactonate | Metabolite | CHEBI:12931 (ChEBI) | |
GALE | GeneProduct | ENSG00000117308 (Ensembl) | |
GALK1 | GeneProduct | ENSG00000108479 (Ensembl) | |
GALT | GeneProduct | ENSG00000213930 (Ensembl) | |
GBE1 | GeneProduct | ENSG00000114480 (Ensembl) | glycogen branching enzyme that catalyzes the transfer of alpha-1,4-linked glucosyl units from the outer end of a glycogen chain to an alpha-1,6 position on the same or a neighboring glycogen chain |
GYG1 | GeneProduct | ENSG00000163754 (Ensembl) |
|
GYG2 | GeneProduct | ENSG00000056998 (Ensembl) | expressed mainly in liver, cardiac muscle and other types of tissue, but not in skeletal muscle. |
GYS1 | GeneProduct | ENSG00000104812 (Ensembl) |
|
GYS2 | GeneProduct | ENSG00000111713 (Ensembl) | GYS2: specific to liver |
Galactitol | Metabolite | HMDB0000107 (HMDB) | |
Galactose-1-phosphate | Metabolite | CHEBI:17973 (ChEBI) | |
Glucose-1-phosphate | Metabolite | CHEBI:16077 (ChEBI) | |
Glucose-6-phosphate | Metabolite | HMDB0001401 (HMDB) |
|
Glycogen synthesis and degradation | Pathway | WP500 (WikiPathways) | |
Glycogen | Metabolite | CHEBI:28087 (ChEBI) | |
PGM1 | GeneProduct | ENSG00000079739 (Ensembl) | |
PYGL | GeneProduct | ENSG00000100504 (Ensembl) | |
SLC2A2 | GeneProduct | ENSG00000163581 (Ensembl) | |
SLC5A1 | GeneProduct | ENSG00000100170 (Ensembl) | |
UDP-galactose | Metabolite | CHEBI:67119 (ChEBI) | |
UDP-glucose | Metabolite | CHEBI:18066 (ChEBI) | |
galactose dehydrogenase | Protein | 1.1.1.48 (Enzyme Nomenclature) | "This enzyme is part of the De Ley-Doudoroff pathway, which is used by some bacteria during growth on D-galactose." Source: [https://enzyme.expasy.org/EC/1.1.1.48] |
galactose | Metabolite | CHEBI:28260 (ChEBI) | |
glycogen (n+1) | Metabolite | 9005-79-2 (CAS) |
Annotated Interactions
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Source | Target | Type | Database reference | Comment |
---|---|---|---|---|
Galactose-1-phosphate | Glucose-1-phosphate | mim-conversion | 13990 (Rhea) | |
Glucose-1-phosphate | mim-conversion | 23536 (Rhea) | ||
Glucose-6-phosphate | mim-conversion | 23536 (Rhea) | ||
Glycogen | Glucose-1-phosphate | mim-conversion | 41732 (Rhea) | |
UDP-galactose | mim-conversion | 22170 (Rhea) | ||
UDP-glucose | glycogen (n+1) | mim-conversion | 18550 (Rhea) | |
UDP-glucose | mim-conversion | 19892 (Rhea) | ||
UDP-glucose | mim-conversion | 22169 (Rhea) | ||
galactose | D-galactonate | mim-conversion | Q22281942 (Wikidata) | |
galactose | Galactitol | mim-conversion | 37965 (Rhea) | |
galactose | Galactose-1-phosphate | mim-conversion | 13554 (Rhea) | |
glycogen (n+1) | Glycogen | mim-conversion | R-HSA-3322016.3 (Reactome) |