An automatic transmission shifter assembly comprises a shift lever support configured for attachment to a vehicle, a shift lever mounted to the shift lever support to shift between transmission gear settings; a brake transmission system interlock (BTSI) comprising a shift lever control member controllable by actuation of a solenoid or other powered actuator to selectively block the shift lever from moving out of the PARK position. An electronic ignition switch, an ignition actuator and an ignition key interlock are mounted to the shift lever support. The ignition key interlock comprises an interlock member controllable by the ignition actuator to selectively block the solenoid from moving the shift lever control member to the unblock position.