Journal article
Differential Regulation of Gene Expression by PITX2 Isoforms
The Journal of biological chemistry, Vol.277(28), pp.25001-25010
07/12/2002
DOI: 10.1074/jbc.M201737200
PMID: 11948188
Abstract
Three major PITX2 isoforms are differentially expressed in human, mice, zebrafish, chick, and frog tissues. To demonstrate differential regulation of gene expression by these isoforms we used three different promoters and three cell lines. Transient transfection of Chinese hamster ovary, HeLa, and LS-8 cell lines revealed differences in PITX2A and PITX2C activation of thePLOD1 and Dlx2 promoters, however, PITX2B is inactive. In contrast, PITX2B actives the pituitary-specificProlactin promoter at higher levels than either PITX2A or PITX2C. Interestingly, co-transfection of either PITX2A orPITX2C with PITX2B results in a synergistic activation of the PLOD1 and Dlx2 promoters. Furthermore, PITX2 isoforms have different transcriptional activity dependent upon the cells used for transfection analysis. We have isolated a fourth PITX2 isoform (PITX2D) expressed only in humans, which acts to suppress the transcriptional activity of the other PITX2 isoforms. Electrophoretic mobility shift assays and glutathione S-transferase pull-down experiments demonstrated that all isoforms interact with PITX2D and that PITX2B forms heterodimeric complexes with PITX2A and PITX2C. Our research provides a molecular basis for differential gene regulation through the expression of PITX2 isoforms. PITX2 isoform activities are both promoter- and cell-specific, and our data reveal new mechanisms for PITX2-regulated gene expression.
Details
- Title: Subtitle
- Differential Regulation of Gene Expression by PITX2 Isoforms
- Creators
- Carol J. Cox - University of TulsaHerbert M. Espinoza - University of TulsaBryan McWilliams - University of TulsaKimberly Chappell - University of TulsaLisa Morton - University of TulsaTord A. Hjalt - University of IowaElena V. Semina - University of IowaBrad A. Amendt - University of Tulsa
- Resource Type
- Journal article
- Publication Details
- The Journal of biological chemistry, Vol.277(28), pp.25001-25010
- DOI
- 10.1074/jbc.M201737200
- PMID
- 11948188
- NLM abbreviation
- J Biol Chem
- ISSN
- 0021-9258
- eISSN
- 1083-351X
- Publisher
- Elsevier Inc
- Language
- English
- Date published
- 07/12/2002
- Academic Unit
- Orthodontics; Anatomy and Cell Biology; Craniofacial Anomalies Research Center; Dental Research
- Record Identifier
- 9984284329002771
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