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UDP-galactose pyrophosphorylase in mice with galactose-1-phosphate uridyltransferase deficiency.
Mol Genet Metab. 2005 May; 85(1):21-7.MG

Abstract

UDP-glucose pyrophosphorylase (E.C. 2.7.7.9), encoded by ugp, provides UDP-glucose which is critical to the synthesis of glycogen, and also catalyzes the reaction between UTP and galactose-1-phosphate, yielding UDP-galactose. This activity of UDP-gal pyrophosphorylase (UDP-galPP) suggests a role in an alternate pathway for galactose metabolism in patients with deficiency of galactose-1-phosphate uridyltransferase (GALT). We examined the effects of GALT deficiency and dietary galactose on UDP-glucose pyrophosphorylase (UDP-gluPP) and UDP-galactose pyrophosphorylase activity and ugp expression in liver of mice with homozygous deletion of the critical regions of galt. Activity with glucose-1-phosphate as substrate was significantly higher than that with galactose-1-phosphate. In liver from mice with GALT deficiency (G/G), UDP-galPP activity appeared to be lower than that measured in liver from control (N/N) animals. This difference disappeared when the N/N tissue homogenate was dialyzed to remove residual UDP-glucose, confirming that careful elimination of residual GALT activity is necessary, since GALT has 1000-fold greater activity toward galactose-1-phosphate than that of UDP-galPP in liver homogenates. Prior exposure to conventional mouse chow, high galactose chow, and high glucose chow did not alter UDP-glu PP or UDP-galPP activity. Steady state UGP mRNA levels were determined in tissues from normal and G/G animals. UGP expression was highest in liver, and did not differ by genotype or exposure to high galactose chow. UDP-galPP activity may account for unexplained ability to oxidize galactose in animals with no GALT activity, but is insufficient to alter accumulation of galactose metabolites.

Authors+Show Affiliations

Division of Human Genetics, Cincinnati Children's Hospital Research Foundation, Cincinnati, OH 45229, USA. nancy.leslie@cchmc.orgNo affiliation info availableNo affiliation info availableNo affiliation info available

Pub Type(s)

Journal Article
Research Support, N.I.H., Extramural
Research Support, U.S. Gov't, P.H.S.

Language

eng

PubMed ID

15862277

Citation

Leslie, Nancy, et al. "UDP-galactose Pyrophosphorylase in Mice With Galactose-1-phosphate Uridyltransferase Deficiency." Molecular Genetics and Metabolism, vol. 85, no. 1, 2005, pp. 21-7.
Leslie N, Yager C, Reynolds R, et al. UDP-galactose pyrophosphorylase in mice with galactose-1-phosphate uridyltransferase deficiency. Mol Genet Metab. 2005;85(1):21-7.
Leslie, N., Yager, C., Reynolds, R., & Segal, S. (2005). UDP-galactose pyrophosphorylase in mice with galactose-1-phosphate uridyltransferase deficiency. Molecular Genetics and Metabolism, 85(1), 21-7.
Leslie N, et al. UDP-galactose Pyrophosphorylase in Mice With Galactose-1-phosphate Uridyltransferase Deficiency. Mol Genet Metab. 2005;85(1):21-7. PubMed PMID: 15862277.
* Article titles in AMA citation format should be in sentence-case
TY - JOUR T1 - UDP-galactose pyrophosphorylase in mice with galactose-1-phosphate uridyltransferase deficiency. AU - Leslie,Nancy, AU - Yager,Claire, AU - Reynolds,Robert, AU - Segal,Stanton, Y1 - 2005/02/23/ PY - 2004/11/11/received PY - 2005/01/12/revised PY - 2005/01/12/accepted PY - 2005/5/3/pubmed PY - 2005/9/27/medline PY - 2005/5/3/entrez SP - 21 EP - 7 JF - Molecular genetics and metabolism JO - Mol Genet Metab VL - 85 IS - 1 N2 - UDP-glucose pyrophosphorylase (E.C. 2.7.7.9), encoded by ugp, provides UDP-glucose which is critical to the synthesis of glycogen, and also catalyzes the reaction between UTP and galactose-1-phosphate, yielding UDP-galactose. This activity of UDP-gal pyrophosphorylase (UDP-galPP) suggests a role in an alternate pathway for galactose metabolism in patients with deficiency of galactose-1-phosphate uridyltransferase (GALT). We examined the effects of GALT deficiency and dietary galactose on UDP-glucose pyrophosphorylase (UDP-gluPP) and UDP-galactose pyrophosphorylase activity and ugp expression in liver of mice with homozygous deletion of the critical regions of galt. Activity with glucose-1-phosphate as substrate was significantly higher than that with galactose-1-phosphate. In liver from mice with GALT deficiency (G/G), UDP-galPP activity appeared to be lower than that measured in liver from control (N/N) animals. This difference disappeared when the N/N tissue homogenate was dialyzed to remove residual UDP-glucose, confirming that careful elimination of residual GALT activity is necessary, since GALT has 1000-fold greater activity toward galactose-1-phosphate than that of UDP-galPP in liver homogenates. Prior exposure to conventional mouse chow, high galactose chow, and high glucose chow did not alter UDP-glu PP or UDP-galPP activity. Steady state UGP mRNA levels were determined in tissues from normal and G/G animals. UGP expression was highest in liver, and did not differ by genotype or exposure to high galactose chow. UDP-galPP activity may account for unexplained ability to oxidize galactose in animals with no GALT activity, but is insufficient to alter accumulation of galactose metabolites. SN - 1096-7192 UR - https://www.unboundmedicine.com/medline/citation/15862277/UDP_galactose_pyrophosphorylase_in_mice_with_galactose_1_phosphate_uridyltransferase_deficiency_ L2 - https://linkinghub.elsevier.com/retrieve/pii/S1096-7192(05)00042-9 DB - PRIME DP - Unbound Medicine ER -