Human fructose-1,6-bisphosphatase gene (FBP1): Exon-intron organization, localization to chromosome bands 9q22.2-q22.3, and mutation screening in subjects with fructose-1,6-bisphosphatase deficiency

Journal Article · Sat Jun 10 04:00:00 EDT 1995 · Genomics

DOI:https://doi.org/10.1006/geno.1995.1085· OSTI ID:273443

El-Maghrabi, M R; Jiang, W ^[1]

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1. State Univ. of New York, Stony Brook, NY (United States); and others

Fructose-1,6-bisphosphatase (EC 3.1.3.11) is a key regulatory enzyme of gluconeogenesis that catalyzes the hydrolysis of fructose-1,6-bisphosphate to generate fructose-6-phosphate and inorganic phosphate. Deficiency of fructose-1,6-bisphosphatase is associated with fasting hypoglycemia and metabolic acidosis because of impaired gluconeogenesis. We have cloned and characterized the human liver fructose-1,6-bisphosphatase gene (FBP1). FBP1, localized to chromosome bands 9q22.2-q22.3 by fluorescence in situ hybridization, consists of seven exons that span > 31 kb, and the six introns are in the same position as in the rat gene. FBP1 was screened for mutations in two subjects with fructose-1,6-bisphosphatase deficiency. Four nucleotide substitutions were identified, two of which were silent mutations in the codons for Ala-216 (GCT {yields} GCC) and Gly-319 (GGG {yields} GGA). The other substitutions were in intron 3, a C {yields} T substitution 7 nucleotides downstream from the splice donor site, and in the promoter region, an A {yields} T substitution 188 nucleotides upstream from the start of transcription. These nucleotide substitutions were also found in normal unaffected subjects and thus are not the cause of fructose-1,6-bisphosphatase deficiency in the two subjects studied. The molecular basis of hepatic fructose-1,6-bisphosphatase deficiency in these subjects remains undetermined but could result from unidentified mutations in the promoter that decrease expression or from mutations in another gene that indirectly lead to decreased fructose-1,6-bisphosphatase activity. 18 refs., 3 figs., 3 tabs.

• OSTI ID: 273443
• Journal Information: Genomics, Journal Name: Genomics Journal Issue: 3 Vol. 27; ISSN GNMCEP; ISSN 0888-7543
• Country of Publication: United States
• Language: English

Related Subjects

55 BIOLOGY AND MEDICINE
BASIC STUDIES
AMINO ACIDS
CODONS
DNA HYBRIDIZATION
DNA-CLONING
ENZYMES
EXONS
FLUORESCENCE
FRUCTOSE
GENE MUTATIONS
GENE REGULATION
GENES
GENETIC MAPPING
HEREDITARY DISEASES
HUMAN CHROMOSOME 9
INTRONS
METABOLIC DISEASES
NUCLEOTIDES
PATIENTS
STRUCTURE-ACTIVITY RELATIONSHIPS