Recast, so got part in title role (11)
I believe the answer is:
protagonist
'title role' is the definition.
'recast so got part in' is the wordplay.
'recast' indicates an anagram.
'so'+'got'+'part'+'in'='sogotpartin'
'sogotpartin' anagrammed gives 'PROTAGONIST'.
(Other definitions for protagonist that I've seen before include "Advocate" , "Chief character in a story" , "Key character in a novel" , "Lead character" , "champion" .)