title: Disruption of a novel regulatory element in the erythroid-specific promoter of the human PKLR gene causes severe pyruvate kinase deficiency.
abstract: We established the molecular basis for pyruvate kinase (PK) deficiency in a white male patient with severe nonspherocytic hemolytic anemia. The paternal allele exhibited the common PKLR cDNA sequence (c.) 1529G>A mutation, known to be associated with PK deficiency. On the maternal allele, 3 in cis mutations were identified in the erythroid-specific promoter region of the gene: one deletion of thymine -248 and 2 single nucleotide substitutions, nucleotide (nt) -324T>A and nt -83G>C. Analysis of the patient's RNA demonstrated the presence of only the 1529A allele, indicating severely reduced transcription from the allele linked to the mutated promoter region. Transfection of promoter constructs into erythroleukemic K562 cells showed that the most upstream -324T>A and -248delT mutations were nonfunctional polymorphisms. In contrast, the -83G>C mutation strongly reduced promoter activity. Site-directed mutagenesis of the promoter region revealed the presence of a putative regulatory element (PKR-RE1) whose core binding motif, CTCTG, is located between nt -87 and nt -83. Electrophoretic mobility shift assay using K562 nuclear extracts indicated binding of an as-yet-unidentified trans-acting factor. This novel element mediates the effects of factors necessary for regulation of pyruvate kinase gene expression during red cell differentiation and maturation.
authors.affiliation: Department of Clinical Chemistry, University Medical Center Utrecht, The Netherlands.
authors.forename: Richard
authors.initials: R
authors.lastname: van Wijk
authors.forename: Wouter W
authors.initials: WW
authors.lastname: van Solinge
authors.forename: Claus
authors.initials: C
authors.lastname: Nerlov
authors.forename: Ernest
authors.initials: E
authors.lastname: Beutler
authors.forename: Terri
authors.initials: T
authors.lastname: Gelbart
authors.forename: Gert
authors.initials: G
authors.lastname: Rijksen
authors.forename: Finn C
authors.initials: FC
authors.lastname: Nielsen
mesh_terms: D000483:Alleles; D000743:Anemia, Hemolytic / Q000201:enzymology / Q000235:genetics; D001483:Base Sequence; D002648:Child; D003718:Denmark; D004912:Erythrocytes / Q000201:enzymology*; D017353:Gene Deletion; D015870:Gene Expression; D005787:Gene Frequency; D005954:Glucosephosphate Dehydrogenase / Q000097:blood; D006593:Hexokinase / Q000097:blood; D006801:Humans; D004915:Leukemia, Erythroblastic, Acute / Q000235:genetics; D008297:Male; D008969:Molecular Sequence Data; D016297:Mutagenesis, Site-Directed; D011401:Promoter Regions, Genetic; D011770:Pyruvate Kinase / Q000172:deficiency* / Q000235:genetics*; D012045:Regulatory Sequences, Nucleic Acid; D020133:Reverse Transcriptase Polymerase Chain Reaction; D017422:Sequence Analysis, DNA; D014162:Transfection; D014407:Tumor Cells, Cultured
chemical_list: D005954:Glucosephosphate Dehydrogenase; D006593:Hexokinase; D011770:Pyruvate Kinase