Imaging the rapid yet transient accumulation of regulatory lipids lipid kinases and protein kinases during membrane fusion at sites of exocytosis of MMP-9 in MCF-7 cells

摘要

Correlation/ colocalization analysis of secretory vesicles containing MMP9-GFP with lipid sensors tagged with a red-fluorescent protein: a PIP2-sensor; or b DAG-sensor. TIRF images from green channel of MMP9-GFP (left); red channel of either PIP2-mCherry or DAG-mCherry lipid sensor (middle); and merged image (right) from an MCF-7 cell. Scale bar, 10 μm. c Correlation analysis of 23 proteins associated with MMP9-GFP–labeled secretory vesicles in MCF-7 cells, including lipid sensors, lipid kinase isoforms, and protein kinase C isoforms (PRKCs). Red boxes above 0.2 (referenced by the dotted line) indicate proteins associated with secretory vesicles, and boxes below 0.2 represent nonspecifically or not associated proteins. Standard error (SE) is depicted as whiskers and the standard deviation (SD) as × marks