FIG. 6.

Schematic diagram summarizing the signaling pathways that down-regulate caveolin-1 gene expression via transcriptional control. The points of control that are affected by oncogenic activating mutations (Ras, Raf, Src, and Abl) and pharmacological agents (PD 98059, forskolin, and IBMX) are as indicated. RTKs, receptor tyrosine kinases; cAMP, cyclic AMP; NRTKs, nonreceptor tyrosine kinases; GPCRs, G-protein-coupled receptors; PDE, cyclic nucleotide phosphodiesterase. The overall structure of the murine caveolin-1 gene is as we described previously (34–36).