High spatio-temporal resolution measurement of A(1)R and A(2A)R interactions combined with Iem-spFRET and E-FRET methods

A(1)R-A(2A)R heterodimers regulate striatal glutamatergic neurotransmission. However, few researches about kinetics have been reported. Here, we combined Iem-spFRET and E-FRET to investigate the kinetics of A(1)R and A(2A)R interaction. Iem-spFRET obtains the energy transfer efficiency of the whole cell. E-FRET gets energy transfer efficiency with high spatial resolution, whereas, it was prone to biases because background was easily selected due to manual operation. To study the interaction with high spatio-temporal resolution, Iem-spFRET was used to correct the deviation of E-FRET. In this paper, A(1)R and A(2A)R interaction was monitored, and the changes of FRET efficiency of the whole or/and partial cell membrane were described. The results showed that activation of A(1)R or A(2A)R leads to rapid aggregation, inhibition of A(1)R or A(2A)R leads to slow segregation, and the interaction is reversible. These results demonstrated that combination of Iem-spFRET and E-FRET could measure A(1)R and A(2A)R interaction with high spatio-temporal resolution.