‘Fifty Shades\' Film Gets Its Christian and Anastasia

Evan Agostini/AGOEV, via Associated Press Dakota Johnson

Frederick M. Brown/Getty Images Charlie Hunnam

It's a long way from “Ben and Kate” and “Sons of Anarchy” to “Fifty Shades of Grey,” but the model and actress Dakota Johnson and the British actor Charlie Hunnam are about to make that big leap.

E.L. James, the author of the best-selling erotic novel, announced in separate tweets Monday that the pair has been cast in the lead roles of the film adaptation of the first volume of her “Fifty Shades” trilogy, which has sold an estimated 70 million copies worldwide.

Ms. Johnson, the 23-year-old daughter of the television and film stars Don Johnson and Melanie Griffith, will play Anastasia Steele, the initially naïve college student who is introduced to games of sexual dominance and submission by Christian Grey, a wealthy young businessman who will be played by Mr. Hunnam.

There has been widespread speculation in social media and elsewhere about the casting of those roles, and while both Ms. Johnson and Mr. Hunnam had been mentioned, neither was considered the front-runner.

Most recently, Ms. Johnson has been filming a reworking of Shakespeare's “Cymbeline,” which has yet to be released. Besides her role as a single mom in the short-lived sitcom “Ben and Kate,” she has been in “Crazy in Alabama,” “The Social Network” and “21 Jump Street.”

In “Sons of Anarchy,” which begins it sixth season on Sept. 10, Mr. Hunnam plays the president of an outlaw motorcycle club. On screen he's been in “Pacific Rim,” “Cold Mountain” and “Nicholas Nickleby.”

The novelist's tweets did not mention when shooting of the film will start, or who will be cast in supporting roles. But it is to be directed by Sam Taylor-Johnson (“Nowhere Boy”) with Ms. James as one of the producers, and has a scheduled release date of Aug. 1, 2014 in the United States.