Figure 2.

Presynaptic microinjection of FGFR1K. (A) Recordings of PSP and ICa (as in Fig. 1A) before (control) and after microinjection of FGFR1K. (B) Superfusion with genistein (10 μM) produced a significant reduction of both ICa and PSP. (C) Plot of two experiments showing the time course of FGFR1K presynaptic microinjection on ICa (○) and PSP (•) and their reversible block by genistein, as well as the lack of effect of a similar injection using heat-inactivated FGFR1K (▴). (D) PSP elicited by presynaptic stimulation, before (control) and its reduction after postsynaptic microinjection of FGFR1K. (E) (a) Coomasie blue-stained gel of purified FGFR1K. (b) FGFR1K was subjected to autophosphorylation and activation in the presence of [α-³²P]ATP and Mg²⁺. Shown is the autophosphorylation of activated FGFR1K analyzed by SDS/PAGE and autoradiography.