Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:P06889 (Mol)
 630,302 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Phenylketonuria (PKU) is a metabolic disorder secondary to a deficiency of the hepatic enzyme phenylalanine hydroxylase (PAH). The recent creation of a mouse strain for PAH deficiency has provided an excellent model system to explore the possibility of its phenotypic correction by hepatic gene therapy. A recombinant retrovirus containing the mouse PAH cDNA under the transcriptional control of the human CMV promoter was constructed and used to transduce hepatocytes isolated from PAH-deficient mice. Viral-transduced hepatocytes produced dramatically higher levels of mouse PAH mRNA as compared to control mock-infected hepatocytes. The PAH mRNA was translated efficiently into PAH protein that is capable of converting phenylalanine to tyrosine in vitro. These results demonstrate that the PAH-deficient mouse hepatocytes can be readily reconstituted by retroviral-mediated gene transduction, which is a crucial step towards somatic gene therapy for PKU.
Somat Cell Mol Genet 1992 Jan
PMID:Reconstitution of enzymatic activity in hepatocytes of phenylalanine hydroxylase-deficient mice. 131 61

The application of the tools of molecular biology has led to a profound increase in our current understanding of the nature of the disease states associated with defects in the phenylalanine hydroxylase (PAH) gene. Over the past decade, the PAH cDNA has been cloned and the primary structure of the PAH protein has been determined. The PAH cDNA clone has served as an invaluable probe to define the molecular structure and chromosomal location of the PAH locus in both man and other organisms. Southern analysis using the PAH cDNA as a hybridization probe has revealed the presence of numerous restriction fragment-length polymorphisms (RFLPs) in the PAH gene, which have permitted the classification of normal and mutant PAH chromosomes. RFLP analysis has also permitted the implementation of prenatal diagnosis of phenylketonuria (PKU) and other related hyperphenylalaninemic disorders. Through the use of molecular cloning and polymerase chain reaction methodologies, many molecular lesions have now been identified in the PAH gene, and their association with different PAH haplotypes and disease phenotypes can now be addressed in a rational manner. Finally, the characterization of PAH mutations has enabled the population dynamics of phenylketonuria to be examined in several different populations.
Mol Biol Med 1991 Feb
PMID:Phenylketonuria and the phenylalanine hydroxylase gene. 194 87

A novel substitution has been characterized in the phenylalanine hydroxylase (PAH) gene that is linked exclusively to mutant haplotype 6, which is prevalent in southern Europe but rare in northern and eastern Europe. It is a G-to-A transition in intron 10, 11 bases from exon 11. This substitution creates an additional AG dinucleotide, which may serve as a cryptic splice acceptor site. Individuals who bear this substitution in the homozygous state have a severe PKU phenotype with pretreatment serum phenylalanine levels over 1200 mumol/liter. The frequency and distribution of this substitution among European populations suggests two possible founding populations, one being Middle Eastern and the other Roman. The use of this substitution as a marker to identify PKU chromosomes will be an invaluable aid to carrier screening and prenatal diagnosis in populations where mutant haplotype 6 is prevalent.
Somat Cell Mol Genet 1991 May
PMID:Molecular characterization of PKU allele prevalent in southern Europe and Ireland. 204 41

Phenylketonuria (PKU) is a genetic disorder secondary to a deficiency of hepatic phenylalanine hydroxylase (PAH). Several mutations in the PAH gene have recently been reported, and linkage disequilibrium was observed between RFLP haplotypes and specific mutations. A new molecular lesion has been identified in exon 7 of the PAH gene in a Hungarian PKU patient by direct sequencing of PCR-amplified DNA. The C-to-T transition causes the substitution of Arg243 to a termination codon, and the mutant allele is associated with haplotype 4 of the PAH gene. The mutation is present in two of nine mutant haplotype 4 alleles among Eastern Europeans and is not present among Western Europeans and Asians. The rarity of this mutant allele and its restricted geographic distribution suggest that the mutational event occurred recently on a normal haplotype 4 background in Eastern Europe.
Somat Cell Mol Genet 1990 Jan
PMID:Molecular genetics of PKU in eastern Europe: a nonsense mutation associated with haplotype 4 of the phenylalanine hydroxylase gene. 230 42

Haplotype analysis of the phenylalanine hydroxylase (PAH) gene was performed on 27 chromosomes from a sample of 14 Greek phenylketonuria (PKU) probands and their parents. The majority (94%) of the 17 mutant PAH alleles are on haplotypes 1, 2 and 4, with haplotype 1 being most common. Sixty per cent of ten control PAH alleles are on haplotypes 1, 2 and 4. Haplotype 3 was not present in either group. A new MspI restriction site was found in exon 9 of a single mutant PAH allele on haplotype 7. The mutation responsible for the restriction site alteration is a T to C transition at nucleotide 1154 of the PAH cDNA, resulting in the conversion of codon 311 from leucine to proline (L311P). The same mutation has been described on a haplotype 1 allele in a German PKU patient. A single crossover event would be required to transfer this mutation from haplotype 1 to 7. Migration of this mutation from one haplotype to another by recombination cannot be distinguished from a recurrent mutation at this site.
Mol Biol Med 1989 Jun
PMID:Phenylketonuria in the Greek population. Haplotype analysis of the phenylalanine hydroxylase gene and identification of a PKU mutation. 261 49

A cDNA clone for rabbit tryptophan hydroxylase was used as a probe to identify human tryptophan hydroxylase gene fragments in a panel of hamster-human somatic cell hybrids and determine its chromosomal location in man. A single locus was identified for tryptophan hydroxylase on chromosome 11. Tryptophan hydroxylase is a member of the superfamily of pterin-dependent aromatic amino acid hydroxylases which includes tyrosine hydroxylase, located at 11p15.5-p15, and phenylalanine hydroxylase, located at 12q22-q24.1 in human. The locations of these genes and the evolutionary distance between their sequences suggest that at least three distinct genetic events have occurred during the evolution of the aromatic amino acid hydroxylase superfamily: two sequential gene duplications giving rise to the three distinct hydroxylase loci, and a translocation which separated the tryptophan and tyrosine hydroxylase loci on chromosome 11 from the phenylalanine hydroxylase locus on chromosome 12.
Somat Cell Mol Genet 1987 Sep
PMID:Assignment of human tryptophan hydroxylase locus to chromosome 11: gene duplication and translocation in evolution of aromatic amino acid hydroxylases. 288 73

A cell line, CY-1, was selected in tyrosine free (tyr-) medium after fusion of mouse erythroleukemia (MEL) cells with mitomycin C-treated rat hepatoma cells. MEL cells do not express the enzyme phenylalanine hydroxylase (PH) and are unable to grow in tyr- medium, whereas the rat hepatoma cells constitutively express PH and are able to grow in tyr- medium. CY-1 cells resemble MEL cells morphologically, karyotypically, and in being inducible for hemoglobin synthesis. In contrast to MEL cells, CY-1 expresses PH and is therefore able to grow in tyr- medium. Using a rat cDNA probe for the PH gene, Southern blot analyses were carried out on DNA isolated from CY-1 and parental cells. CY-1 showed the characteristic mouse PH gene pattern but the gene copy number was amplified four- to eightfold compared to parental MEL cells.
Somat Cell Mol Genet 1985 May
PMID:Amplification and expression of phenylalanine hydroxylase in mouse erythroleukemia cells. 298 35

Cells deficient in phenylalanine hydroxylase (PAH) are tyrosine auxotrophs and will not survive in tyrosine-free media. PAH activity can be constituted in cultured cells by infection with recombinant retroviruses carrying a human PAH cDNA. Mouse hepatoma cells transformed with recombinant PAH will grow in tyrosine-free media since these cells constitutively synthesize the cofactor tetrahydrobiopterin which is essential for PAH activity. NIH3T3 cells transformed with the PAH cDNA express the PAH apoenzyme, but this enzyme is inactive in vivo since these cells do not synthesize biopterin. We describe a method of selection for PAH in the fibroblast-like NIH3T3 cells involving tyrosine-free media supplemented with biopterin, reducing agents, and antioxidants. Cells transformed with the recombinant PAH gene exhibit PAH activity in culture and will grow in the biopterin-supplemented tyrosine-free media. Metabolic selection for PAH activity provides a new selectable marker for gene transfer experiments. This method is shown to be useful in the production of high titers of recombinant retroviruses carrying PAH and provides a model for experiments in somatic gene therapy of phenylketonuria.
Somat Cell Mol Genet 1987 Mar
PMID:Selection for phenylalanine hydroxylase activity in cells transformed with recombinant retroviruses. 347 Sep 52

Two crystal habits, one rod shaped and the other square prismatic, of the Fab fragment of a monoclonal anti-phenylalanine hydroxylase antibody have been grown using the method of vapour phase diffusion against polyethylene glycol 6000. The square prisms diffract to better than 2.8 A, belong to the space group P1 and have unit cell parameters a = 41.8 A, b = 50.3 A, c = 114.7 A, alpha = 97.6 degrees, beta = 91.7 degrees, gamma = 91.0 degrees, while the rod-shaped crystals belong to the space group P212121, have unit cell parameters a = 105.6 A, b = 119.8 A, c = 82.2 A and diffract to 3.5 A resolution.
J Mol Biol 1985 Nov 20
PMID:Crystallization and preliminary crystallographic data of the Fab fragment of an anti-phenylalanine hydroxylase monoclonal antibody. 408

RNA single-strand conformation polymorphism (rSSCP) is a recently developed method for detecting genetic defects. This technique requires DNA amplification with a polymerase chain reaction making use of one T7 promoter-containing primer. Amplification products are subsequently transcribed in vitro and the labelled transcripts are analysed for single-strand conformation changes. rSSCP has been applied to mutation screening of the phenylalanine hydroxylase gene and rBAT cDNA, from PKU and cystinuric patients, respectively. Experimental evidence shows that 83% and 86% of screened PKU and cystinuric mutations, respectively, give rise to detectable rSSCP signals. Thus, results obtained show that RNA single-strand conformation polymorphism analysis is generally applicable and is a suitable technique for detecting genetic disease causing mutations, both in basic research and in clinical practice.
Mol Cell Probes 1995 Jun
PMID:Molecular screening of genetic defects with RNA-SSCP analysis: the PKU and cystinuria model. 747 14


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