Mark holds record in warehouse (5)
I believe the answer is:
depot
'warehouse' is the definition.
(I know that warehouse can be written as depot)
'mark holds record' is the wordplay.
'mark' becomes 'dot' (dotting is a kind of marking).
'holds' indicates putting letters inside.
'record' becomes 'EP' (abbreviation for extended play record).
'dot' enclosing 'ep' is 'DEPOT'.
'in' acts as a link.
(Other definitions for depot that I've seen before include "bus terminus" , "Opted (anag)" , "Store for large quantities" , "Military HQ" , "(Military) store" .)