Expression and post-translational modification of human 4-hydroxy-phenylpyruvate dioxygenase.
4-hydroxyphenylpyruvate dioxygenase (HPD) (EC 1.13.11.27) is a key enzyme involved in tyrosine catabolism. Congenital HPD deficiency is a rare, relatively benign condition known as hereditary type III tyrosinemia. The severe type I tyrosinemia, caused by a deficiency of fumarylacetoacetate hydrolase which functions downstream of HPD in the tyrosine degradation pathway, is often associated with decreased expression of HPD, and interestingly, inhibition of HPD activity seems to ameliorate the clinical symptoms of type I tyrosinemia. The HPD gene was previously mapped to the chromosomal region 12q24-->qter. In the present study high-resolution chromosome mapping localized the HPD gene to 12q24.31. DNase I footprinting, revealed that four regions of the HPD promoter were protected by rat liver nuclear proteins. Computer-assisted analyses suggested that these elements might bind Sp1/AP2, HNF4, HNF3/CREB, and C/EBP, respectively. In transient transfection experiments, the proximal 271bp of the promoter conferred basal transcriptional activation in human Chang cells. Sequences in intron 1 were able to enhance the activity of this basal promoter. Finally, vaccinia virus-based expression provided evidence that HPD is subject to phosphorylation, and furthermore, allowed mapping of the HPD protein in the human keratinocyte 2D database.
Aarenstrup
Lene
L
Department of Biochemistry and Molecular Biology, University of Southern Denmark, Campusvej 55, DK-5230, Odense M, Denmark.
Falch
Anne Marie
AM
Jakobsen
Kirsten K
KK
Neve
Søren
S
Henriksen L
Linda Ø
LØ
Tommerup
Niels
N
Leffers
Henrik
H
Kristiansen
Karsten
K
D015111:4-Hydroxyphenylpyruvate Dioxygenase / Q000235:genetics* / Q000378:metabolism; D000818:Animals; D001483:Base Sequence / Q000235:genetics; D002467:Cell Nucleus / Q000201:enzymology / Q000235:genetics*; D002478:Cells, Cultured; D002874:Chromosome Mapping; D002881:Chromosomes, Human, Pair 12 / Q000235:genetics*; D003001:Cloning, Molecular; D004268:DNA-Binding Proteins / Q000235:genetics; D015971:Gene Expression Regulation, Enzymologic / Q000235:genetics; D006801:Humans; D007438:Introns / Q000235:genetics; D008297:Male; D008969:Molecular Sequence Data; D009154:Mutation / Q000235:genetics*; D011401:Promoter Regions, Genetic / Q000235:genetics; D014176:Protein Biosynthesis / Q000235:genetics*; D023302:Protein Footprinting; D051381:Rats; D017207:Rats, Sprague-Dawley; D013347:Subcellular Fractions; D020176:Tyrosinemias / Q000201:enzymology / Q000235:genetics*
D004268:DNA-Binding Proteins; D015111:4-Hydroxyphenylpyruvate Dioxygenase