FRET analysis of MT1-MMP/CD151 association. (A) Confocal fluorescence images showing the subcellular localization of MT1-MMP-CFP and CD151-YPF fusion proteins in primary HUVECs. Right panel shows FRET efficiency images by acceptor photobleaching of the areas depicted with a red square on the YFP image. The blue square corresponds to the background FRET efficiency in a nonbleached region. Pseudocolor scale is depicted at the left of the FRET image. (B) Chart depicts the quantification of FRET efficiency by acceptor photobleaching in HeLa and HUVECs for the pairs MT1-MMP-CFP/CD151-YFP and MT1-MMP-CFP/CD9-YFP. Data shown are mean plus or minus SE of n = 3 for HUVECs and n = 8 for HeLa. (C) Chart depicts the quantification of FRET efficiency by acceptor photobleaching in HeLa cells for the pairs α3 integrin-CFP/CD151-YFP; MT1-MMP-CFP/CD151-YFP; α3 integrin-CFP/MT1-MMP-YFP, and MT1-MMP-CFP/CD9-YFP. Data shown are mean plus or minus SE of n = 8.