Coming from a family steeped in the business, Jake Gyllenhaal knows the routine. When it comes to promoting a film, you can never say enough good things about your co-stars.

“It’s true, actors do this stuff: ‘Oh, he’s great — he pisses lemonade and he shits rainbows,”‘ he says.

But no more. Such was the positive experience Gyllenhaal enjoyed with his new best buddy Tobey Maguire in Brothers, he’s committed to working on projects where the camaraderie is real.

“I don’t believe any more I can make a movie when I don’t care … about the other people in the process,” says the actor, whose father is a director, his mother a writer and sister is the Oscar-nominated Maggie Gyllenhaal. “I don’t think I’m any good when I don’t interact.”

Once poised to take over from Maguire in the Spider-Man franchise, 29-year-old Gyllenhaal credits his on-screen brother for initiating a meaningful and professionally rich relationship when the pair decided to do the film.

“We’d work out together, we’d play basketball together,” Gyllenhaal says. “Not only is he a great actor, he’s also a great producer in some ways.

“He’s 100 per cent always involved.”

Gyllenhaal’s career has remained buoyant since he was nominated for an Oscar alongside Heath Ledger for Brokeback Mountain in 2005, although he’s yet to become the next ubiquitous Hollywood star as many had expected. Ironically, Gyllenhaal turned down the lead role in the blockbuster Avatar but with a raft of diverse roles, including the big-budget Prince of Persia: The Sands of Time, coming to screens this year, he is destined to reinforce his reputation as a marquee name.

“Working on a movie like Prince of Persia was awesome,” he says. “It was really great fun to be like an action hero, jump around and run off walls and fight bad guys, have great quippy lines. Wearing half your clothes is always really fun.”

Gyllenhaal worked furiously for seven months to hone his physique for the fantasy adventure movie, based on the video game series of the same name. The $US150 million ($164 million) film is scheduled for a May release.

He has other significant films in the can, among them Love and Other Drugs with Anne Hathaway and the comedy Nailed alongside Jessica Biel.

Gyllenhaal is now shooting sci-fi thriller Source Code, capping a hectic 12 months during which time he also split from his partner, Reese Witherspoon.

“Whatever I dreamed and hoped for in my career and life is not how it’s gone in a lot of ways and I love that.”