Fig. 3

Sp1 expression and activity are elevated by cav-1 deletion. a Predicted Sp1 transcription factor binding sites within the -123 bp region of the FST promoter are shown. Sp1 protein expression was significantly increased in cav-1 KO compared to WT MC as assessed by western blotting of total cell lysate (n = 12, *p < 0.05) (b) and nucleus (n = 5, *p < 0.05) (c), as well as by immunofluorescence microscopy (n = 5, *p < 0.05, representative micrographs shown) (d). e Sp1 activity, as assessed by the Sp1 reporter construct Sp1-luc, was elevated in cav-1 KO MC (n = 16, *p < 0.05). f Sp1 expression and nuclear localization (arrows) were elevated in the kidneys of cav-1 KO mice, seen in both glomeruli (magnified glomerular area shown within dotted box) and tubules (n = 3 mice, *p < 0.05, representative micrographs shown). g Cav-1 knockdown in WT MC significantly increased Sp1 activity compared with control siRNA-transfected KO MC (n = 6, *vs KO, #vs WT con siRNA, p < 0.05)