Pleiomorphic adenoma gene-like-2, a zinc finger protein, transactivates the surfactant protein-C promoter.
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 gene-like (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-1-independent manner. Both human and mouse SP-C promoters, but not the SP-B promoter, could be activated by PLAGL2 in transfected human embryonic kidney-293 (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.
Yang
Meng-Chun W
MC
Department of Internal Medicine, Pulmonary and Critical Care Medicine, The University of Texas Southwestern Medical Center at Dallas, Dallas, Texas 75390-9034, USA.
Weissler
Jonathan C
JC
Terada
Lance S
LS
Deng
Feitao
F
Yang
Yih-Sheng
YS
D000818:Animals; D001483:Base Sequence; D002478:Cells, Cultured; D004268:DNA-Binding Proteins / Q000235:genetics / Q000378:metabolism*; D024202:Electrophoretic Mobility Shift Assay; D017930:Genes, Reporter / Q000235:genetics; D006801:Humans; D051379:Mice; D008969:Molecular Sequence Data; D009687:Nuclear Proteins; D011401:Promoter Regions, Genetic; D011663:Pulmonary Surfactants / Q000378:metabolism*; D016601:RNA-Binding Proteins / Q000235:genetics / Q000378:metabolism*; D012045:Regulatory Sequences, Nucleic Acid / Q000235:genetics*; D000074482:Thyroid Nuclear Factor 1; D014157:Transcription Factors / Q000235:genetics / Q000378:metabolism*; D015003:Yeasts / Q000378:metabolism
D004268:DNA-Binding Proteins; C000614412:NKX2-1 protein, human; C000614414:Nkx2-1 protein, mouse; D009687:Nuclear Proteins; C114598:PLAGL2 protein, human; D011663:Pulmonary Surfactants; D016601:RNA-Binding Proteins; D000074482:Thyroid Nuclear Factor 1; D014157:Transcription Factors