Notwithstanding any other law to the contrary, a state executive or administrative officer, or the head of a department, commission, board or other state agency, may appoint in writing a deputy or other employee of his department to serve in his place as a member of any board, commission or agency of which he is made by law an ex officio member. When the initial executive reorganization is completed pursuant to section 2 of article 5 of the state constitution such appointment shall only be made by the head of the department. The appointment may be made for a specific meeting or meetings or a specific period of time or until revoked by the official making the appointment but such appointment shall terminate whenever the appointing official is no longer eligible to serve in such capacity.