Figure 4. In vivo assembly of CFP-/YFP-labelled rCaT1 proteins and of their CFP-/YFP-labelled N-terminal fragments.

HEK cells were cotransfected with CFP- and YFP-labelled CaT1 (A) or CFP- and YFP-labelled N-terminal rCaT1 fragments (B). Representative CFP_excit/CFP_emis (1), CFP_excit/YFP_emis (2, FRET), and YFP_excit/YFP_emis (3) images and the corrected FRET image (4, nFRET) are shown in A and B. For control, transfection was carried out with CFP and YFP-rCaT1 (C) or CFP and YFP-N₁₉₈-rCaT1 (D). On average, CFP-/YFP-rCaT1 (C) and CFP-/YFP-N₁₉₈-rCaT1 (D) cotransfected cells showed a significantly higher nFRET when calculated for the whole HEK cell in comparison to control. n denotes the number of cells analysed.