Published ahead of print on September 10, 2004, doi:10.1165/rcmb.2003-0422OC
© 2005 American Thoracic Society DOI: 10.1165/rcmb.2003-0422OC Pleiomorphic Adenoma GeneLike2, a Zinc Finger Protein, Transactivates the Surfactant ProteinC PromoterDepartment of Internal Medicine, Pulmonary and Critical Care Medicine, The University of Texas Southwestern Medical Center at Dallas; and Dallas Veterans Affairs Medical Center, Dallas, Texas Correspondence and requests for reprints should be addressed to Yih-Sheng Yang, Ph.D., Department of Internal Medicine, Pulmonary and Critical Care Medicine, UT Southwestern Medical Center, 5323 Harry Hines Blvd., Dallas, TX 75390-9034. E-mail: Yih-Sheng.Yang{at}UTSouthwestern.edu Expression of surfactant protein (SP)-C occurs principally in type II pneumocytes located in the distal lung alveolae. SP-C expression is thought to be primarily regulated by thyroid transcription factor (TTF)-1 and its associated proteins interacting with a previously defined promoter region between 197 and 158 in mice. We screened a human lung cDNA library using a modified yeast one-hybrid system and identified pleiomorphic adenoma genelike (PLAGL)2, a ubiquitously expressed zinc finger protein, as a transfactor of the SP-C promoter. The PLAGL2 DNA-binding site was located in the SP-C promoter proximal region close to the TTF-1 sites. This site was demonstrated to be functional by use of electrophoresis mobility shift assay, mutagenesis analysis, and transfection studies. PLAGL2 bound to DNA via its N-terminus zinc fingers and activated the SP-C promoter in a TTF-1independent manner. Both human and mouse SP-C promoters, but not the SP-B promoter, could be activated by PLAGL2 in transfected human embryonic kidney293 (HEK293) cells as well as in murine type II (MLE12) cells. The expression of PLAGL2 in isolated human embryonic lung type II cells and its transactivation activity on the SP-C promoter suggest that PLAGL2 may modulate SP-C expression during lung development.
Key Words: gene expression PLAGL2 SP-C TTF-1 zinc finger protein This article has been cited by other articles:
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