Caveolin-1 interacts with protein phosphatase 5 and modulates its activity in prostate cancer cells

Caveolin-1 is highly expressed in prostate cancer cells, and is implicated in disease progression. Here, we identified protein phosphatase 5 (PP5) as a novel cellular binding partner of caveolin-1 using a pull-down approach in combination with mass spectrometry-based proteomic analyses. In situ proximity ligation assays demonstrated co-localization and physical interaction of caveolin-1 and PP5 in the cytoplasm of PC-3 human prostate cancer cells. Using yeast two-hybrid analysis, we found that caveolin-1 interacted with the catalytic domain of PP5. We also found that PP5 activity was elevated about 1.7-fold in the presence of 2 μM caveolin-1, and that the scaffolding domain of caveolin-1 is required for this activation. Our results suggest that caveolin-1 is a novel physiological activator of PP5.

► Protein phosphatase 5 was identified as a novel binding partner of caveolin-1. ► Caveolin-1 interacts with the catalytic domain of protein phosphatase 5. ► Caveolin-1 is a novel physiological activator of protein phosphatase 5.