PITX2 Regulates Procollagen Lysyl Hydroxylase (PLOD) Gene Expression: Implications for the Pathology of Rieger Syndrome

• Published in: The Journal of cell biology 2001-02, Vol.152 (3), p.545-552
• Main Authors: Hjalt, Tord A., Amendt, Brad A., Murray, Jeffrey C.
• Format: Article
• Language: English
• Subjects: Abnormalities, Multiple - genetics; Abnormalities, Multiple - physiopathology; Animals; Base Sequence; Cell Line; Cellular biology; CHO cells; Chromatin; Chromatin - metabolism; Cricetinae; Disease; DNA; Drosophila; Ehlers-Danlos Syndrome - genetics; Ehlers-Danlos Syndrome - physiopathology; Gene expression regulation; Gene Expression Regulation, Enzymologic; Genes; Genes, Reporter - genetics; Genetic vectors; HeLa cells; Homeobox Protein PITX2; Homeodomain Proteins - genetics; Homeodomain Proteins - metabolism; Humans; Lysyl hydroxylase; Mice; Molecular Sequence Data; Multigene Family - genetics; Mutation; Nuclear Proteins; Original; Paired Box Transcription Factors; PITX2 gene; Plasmids; PLOD gene; Polymerase chain reaction; Procollagen-Lysine, 2-Oxoglutarate 5-Dioxygenase - genetics; Procollagen-Lysine, 2-Oxoglutarate 5-Dioxygenase - metabolism; Recombinant Fusion Proteins - metabolism; Regulatory Sequences, Nucleic Acid - genetics; Rieger syndrome; Syndrome; Transcription Factors - genetics; Transcription Factors - metabolism
• ISSN: 0021-9525; 1540-8140
• DOI: 10.1083/jcb.152.3.545

The Rieger syndrome is an autosomal dominant disease characterized by ocular, craniofacial, and umbilical defects. Patients have mutations in PITX2, a paired-bicoid homeobox gene, also involved in left/right polarity determination. In this study we have identified a family of genes for enzymes responsible for hydroxylizing lysines in collagens as one group of likely cognate targets of PITX2 transcriptional regulation. The mouse procollagen lysyl hydroxylase (Plod)-2 gene was enriched for by chromatin precipitation using a PITX2/Pitx2-specific antibody. Plod-2, as well as the human PLOD-1 promoters, contains multiple bicoid (PITX2) binding elements. We show these elements to bind PITX2 specifically in vitro. The PLOD-1 promoter induces the expression of a luciferase reporter gene in the presence of PITX2 in cotransfection experiments. The Rieger syndrome causing PITX2 mutant T68P fails to induce PLOD-1-luciferase. Mutations and rearrangements in PLOD-1 are known to be prevalent in patients with Ehlers-Danlos syndrome, kyphoscoliosis type (type VI [EDVI]). Several of the same organ systems are involved in Rieger syndrome and EDVI.