Biomedical subjects

C Gregori

Publications and source records attributed to C Gregori.

At least 19 recordsLinked to original sources

PubMed1991

Interplay of an original combination of factors: C/EBP, NFY, HNF3, and HNF1 in the rat aldolase B gene promoter.

The rat aldolase B 5' flanking region (nucleotides - 194 to +41) contains sufficient information for liver-specific expression. A detailed investigation of factors binding to the rat aldolase B 5' flanking region has allowed us to identify three distinct factors that filled different sites of this region (A, B, C). The liver-enriched C/EBP or related factors bind to box C, as demonstrated by the specific interaction with bacterially expressed C/EBP protein. Box B bearing the CCAAT sequence binds the ubiquitous factor NFY. Surprisingly, Box A is able to bind two liver enriched factors, namely HNF1 and HNF3. However, in the context of the intact promoter, as shown by footprinting competition experiments, HNF3 binds solely to this sequence. HNF3, but not HNF1 is a transcriptional activator as demonstrated in the in vitro transcription assay.

Animals↗

PubMed1991

Expression of the rat aldolase B gene: a liver-specific proximal promoter and an intronic activator.

The nature and location of the cis-acting DNA sequences regulating expression of the rat aldolase B gene has been investigated. Two liver-specific DNAse I hypersensitive sites were detected, one located just upstream from the cap site, the second in the middle of the first, 4.8-kbp-long, intron. A fragment of 190 bp 5' to the cap site behaved as a tissue-specific but weak core promoter: it directed a detectable reporter gene expression in the Hep G2 cells and hepatocytes, but not in fibroblasts. The tissue-specific expression was stimulated at least 16 fold when constructs contained the entire first intron. The intronic activating sequences could be ascribed to an inner 2 kbp fragment in which the downstream liver-specific DNAse I hypersensitive site was located.

Chloramphenicol O-Acetyltransferase↗

PubMed1990

Molecular analysis of aldolase B genes in hereditary fructose intolerance.

The molecular basis of hereditary fructose intolerance (HFI) was studied in 50 subjects (41 pedigrees, 82 apparently independent mutant alleles of aldolase B) by direct analysis of aldolase B genes amplified by means of the polymerase chain reaction. The mutation A149P (ala 149----pro) was found in 67% of alleles but was significantly more common in patients from northern than from southern Europe. Two other point mutations of aldolase B were identified. A174D (C----A; ala 174----asp) was found in subjects from Italy, Switzerland, and Yugoslavia (overall frequency 16%) but not in those from the United Kingdom, France, or the United States. L288 delta C carried a single base-pair deletion causing frameshift at codon 288 and was restricted to Sicilian subjects. By testing for these mutations in amplified DNA with a limited panel of allele-specific oligonucleotides, more than 95% of HFI patients will be susceptible to genetic diagnosis.

Alleles↗

PubMed1987

Characterization of three optional promoters in the 5' region of the human aldolase A gene.

We undertook cloning and sequencing of the 5' portion of the human aldolase A gene to elucidate the mechanisms that govern synthesis of its different mRNAs. The sequenced gene is the only active gene in human-rodent fibroblastic somatic hybrids, while the other aldolase A-related sequences are inactive. S1 mapping and primer extension analysis enabled us to demonstrate that three promoter regions were implicated in the initiation of different aldolase A mRNAs, differing only in their 5' non-coding extremities. A distal promoter, N (non-specific), governs the synthesis of a 5' non-coding region of 142 bases composed of two exons, N1 and N2, which are found in a variety of tissues. A median promoter, M (muscle), is only active in skeletal muscle, and initiates the transcription by a 5' non-coding exon of 45 bases. Finally, a proximal promoter, H (housekeeping), contained in a "G + C-rich island", permits transcription of three colinear mRNAs containing 172, 126 or 112 bases of 5' non-coding sequence; their expression seems ubiquitous. These three promoters are arranged in 1.5 X 10(3) base-pairs of DNA. Homologies between rat and human genomic sequences and the absence of homology between promoters or 5' non-coding exons of the same species exclude a recent duplication of the promoter regions.

Amino Acid Sequence↗

PubMed1985

[Study of hereditary fructose intolerance by methods of molecular biology].

Fructose intolerance is caused by a deficit of the liver aldolase B enzyme. Its molecular mechanisms were studied at different sites: The protein was studied by a method combining electrophoresis, transfer and immunology. It was present in the 15 cases examined. The genetic variability was demonstrated by the quantitative differences of the immunoreactive proteins. Aldolase messenger RNA was prepared and used to direct in vitro synthesis of human aldolase. Cloning complementary DNA of human aldolase was achieved by using the messenger RNA. Two clones were prepared. The aldolase B gene was then analysed using restriction enzymes in 60 control subjects and 11 patients. An abnormality of the DNA was demonstrated in one of the patients and in her father.

Carbohydrate Metabolism, Inborn Errors↗

PubMed1979

Isoelectrofocusing of erythrocyte galactose 1 phospho uridyl transferase in a family with both galactosemia and Duarte variants.

A family with the presence of the genes for both galactosemia and the Duarte variant is described. Galactose 1 phospho uridyl transferase has been studied not only by electrophoresis on starch gel, but also by isoelectro-focusing on thin-layer acrylamide. Normal and variant transferases were resolved into three bands, the isoelectric point of which was between 5.40 and 5.10 for the normal subjects, and between 5.25 and 4.95 for subjects with the Duarte variant.

Adult↗

PubMed1979