Marx for one turns to Winfrey (5)
I believe the answer is:
harpo
'marx' is the definition.
(Harpo Marx)
'one turns to winfrey' is the wordplay.
'one turns' says the letters should be written backwards.
'to winfrey' becomes 'oprah' (I've seen this in another clue).
'oprah' written backwards gives 'HARPO'.
'for' acts as a link.
(Other definitions for harpo that I've seen before include "The dumb Marx brother" , "One of the Marx Brothers" , "speechless brother" , "The mute Marx Brother" , "one from family of comedians" .)