What leading actors did about Apple stores (2-7)
I believe the answer is:
co-starred
'what leading actors' is the definition.
I can't judge whether this defines the answer.
'did about apple stores' is the wordplay.
'did' becomes 'starred' (starring is a kind of doing).
'about' is a charade indicator (letters next to each other).
'apple stores' becomes 'co' (I am not sure about this - if you are sure you should give a lot more credence to this answer).
'starred' after 'co' is 'CO-STARRED'.
Can you help me to learn more?
(Other definitions for co-starred that I've seen before include "Played the other leading role" , "Shared lead billing" .)