Versatile Pulsed 560 nm Laser Source for Time-Resolved Microscopy and Spectroscopy

Abstract

Here we demonstrate that SPIM-FCS/FCCS possesses the sensitivity to detect and quantify protein-protein interactions in live cells by characterizing the interaction of the subunits of heterodimeric transcription factors, c-Fos/c-Jun and IQGAP/cdc42. The protein-protein interaction clearly shows up in the cross-correlation amplitude. Analysis of the spatial distribution of diffusion coefficients of the fluorescent proteins and of their cross-correlation amplitude shows that formation of the heterodimer is correlated with regions of decreased mobility, probably related to DNA binding.