Coimmunoprecipitation of FAK variants with src and fyn. Src immune complexes (A) or fyn immune complexes (B) were probed for FAK by Western blotting. (A) Src immune complexes from lysates of CE cells (lane 1) or CE cells expressing RCAS B src (lane 2), RCAS A FAK + RCAS B src (lane 3), RCAS A FAK397F + RCAS B src (lane 4), RCAS A FAK576/577FF + RCAS B src (lane 5), RCAS A FAK454R + RCAS B src (lane 6), or RCAS A FAK454R/397F + RCAS B src (lane 7) were analyzed. (B) Fyn immune complexes from lysates of CE cells expressing RCAS B fyn (lane 1), RCAS A FAK + RCAS B fyn (lane 2), RCAS A FAK397F + RCAS B fyn (lane 3), RCAS A FAK454R + RCAS B fyn (lane 4), or RCAS A FAK454R/397F + RCAS B fyn (lane 5) were analyzed.