Graham Fuller, executive editor of Interview magazine, will not be celebrating his 10th anniversary with Andy Warhol’s old rag. “My heart is in writing,” said Fuller, who started with the magazine in June 1990 as a senior editor and was quickly promoted to his present position. He resigned last week, but will not leave until the end of January, covering the Sundance Film Festival for the magazine and putting the March 2000 issue to bed. After that, he will continue writing the monthly magazine’s film column. Fuller has written a number of film books for Faber & Faber, including “Potter on Potter” and “Loach on Loach”; “Leigh on Leigh” will be out next year. Interview editor-in-chief Ingrid Sischy will announce Fuller’s successor shortly.