TY - JOUR
T1 - Induction of AP-1 binding to intron 1 of SP-A1 and SP-A2 is implicated in the phorbol ester inhibition of human SP-A promoter activity
AU - Hoover, Russell R.
AU - Pavlovic, Jelena
AU - Floros, Joanna
PY - 2000/1/1
Y1 - 2000/1/1
N2 - A deletional analysis of the SP-A1 promoter in NCI-H441 cells was performed to identify potential cis-acting elements involved in phorbol ester-mediated repression of human SP-A transcription. The phorbol ester TPA reduced SP-A1 and SP-A2 promoter activity to approximately 35% to 45% compared to that of control cells. The inhibitory effect of TPA was significantly reduced upon removal of the region +64/+394 relative to the SP- A1 transcription start site. Using NCI-H441 nuclear proteins, electromobility shift assay analysis showed that the intron region +309/+329 of SP-A1 and the corresponding region of SP-A2 formed sequence-specific DNA/protein complexes that were induced by TPA exposure. The region +318/+324 of SP-A1 contains sequences similar to a consensus AP-1 binding site, TGACTGA (TCACTGA for SP- A2), which when mutated (TGAGAGT) prevented the formation of the TPA-induced DNA/protein complex. The TPA-induced complex was supershifted in the presence of antibody against the Fun family of proteins, but not the Fos family of proteins. These results suggest that the binding of AP-1 or an AP-1-like factor to the first intron of SP-A1 and SP-A2 may be involved in the phorbol ester inhibition of human SP-A gene expression.
AB - A deletional analysis of the SP-A1 promoter in NCI-H441 cells was performed to identify potential cis-acting elements involved in phorbol ester-mediated repression of human SP-A transcription. The phorbol ester TPA reduced SP-A1 and SP-A2 promoter activity to approximately 35% to 45% compared to that of control cells. The inhibitory effect of TPA was significantly reduced upon removal of the region +64/+394 relative to the SP- A1 transcription start site. Using NCI-H441 nuclear proteins, electromobility shift assay analysis showed that the intron region +309/+329 of SP-A1 and the corresponding region of SP-A2 formed sequence-specific DNA/protein complexes that were induced by TPA exposure. The region +318/+324 of SP-A1 contains sequences similar to a consensus AP-1 binding site, TGACTGA (TCACTGA for SP- A2), which when mutated (TGAGAGT) prevented the formation of the TPA-induced DNA/protein complex. The TPA-induced complex was supershifted in the presence of antibody against the Fun family of proteins, but not the Fos family of proteins. These results suggest that the binding of AP-1 or an AP-1-like factor to the first intron of SP-A1 and SP-A2 may be involved in the phorbol ester inhibition of human SP-A gene expression.
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U2 - 10.1080/019021400408272
DO - 10.1080/019021400408272
M3 - Article
C2 - 10914330
AN - SCOPUS:0033917166
VL - 26
SP - 303
EP - 317
JO - Experimental Lung Research
JF - Experimental Lung Research
SN - 0190-2148
IS - 5
ER -