The lung-specific surfactant protein B gene promoter is a target for thyroid transcription factor 1 and hepatocyte nuclear factor 3, indicating common factors for organ-specific gene expression along the foregut axis.

摘要: We used the lung epithelial cell-specific surfactant protein B (SPB) gene promoter as a model with which to investigate mechanisms involved in transcriptional control of lung-specific genes. In previous study, we showed that SPB specifically activated expression linked reporter continuous H441 cell line and nuclear proteins protected region this from bp -111 -73. further show is complex binding site for thyroid transcription factor 1 (TTF-1) hepatocyte 3 (HNF-3). Whereas TTF-1 bound two highly degenerate closely spaced sites, HNF-3 TGT3 motif (TGTTTGT) also found several liver-specific regulatory regions, where it appears be weak affinity HNF-3. Point mutations these sites eliminated resulted significant decreases transfected activity. addition, developed cotransfection assay family promoters included SPB, SPC, SPA, Clara secretory (CCSP) were by cotransfected TTF-1. conclude are major activators genes propose factors general mechanism transcription. Importantly, data common organ-specific along mammalian foregut axis.