(USA Today) -- Two of the most sought-after roles in Hollywood have been filled.
Dakota Johnson will star as Anastasia Steele and Charlie Hunnam as Christian Grey in the highly anticipated film adaptation of the erotically charged novel Fifty Shades of Grey.
PHOTOS | Dakota Johnson and Charlie Hunnam
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Author E.L. James announced the news on Monday morning in a number of bombshell tweets. She started with Johnson, the daughter of Melanie Griffith and Don Johnson. Distributor Focus Features confirmed it shortly thereafter.
"I am delighted to let you know that the lovely Dakota Johnson has agreed to be our Anastasia in the film adaptation of Fifty Shades of Grey," the first tweet said, ending months of breathless speculation.
Moments later James wrote, "The gorgeous and talented Charlie Hunnam will be Christian Grey in the film adaptation of Fifty Shades of Grey."
The breakthrough announcements over the holiday weekend were the first for the film based on the international best seller, which will be released on Aug. 1, 2014. The two roles have been a longtime source of speculation on the Internet.
As James tweeted before the Monday madness, "Good moaning all. Hold on to your hats..."
The film adaptation is being directed by Sam Taylor-Johnson and produced by Michael De Luca and Dana Brunetti alongside James.
Johnson starred in a memorable, but minor, role in 2010's The Social Network, for which De Luca and Brunetti were producers.
Her subsequent roles include Need for Speed, 21 Jump Street and The Five-Year Engagement. She also starred as Kate in the 2012-13 comedy series Ben and Kate. She is currently shooting a new adaptation of Cymbeline.
The British Hunnam currently stars as Jackson "Jax" Teller on the FX series Sons of Anarchy. His feature film credits include Pacific Rim, Children of Men, Cold Mountain and Nicholas Nickleby.
For months speculation has raged about who would play the two main leads. The other possibilities for Anastasia - a clumsy, innocent college student who enters the highly erotic relationship with Grey - included Emma Watson, Shailene Woodley and Analeigh Tipton.
The Watson rumors were so strong that in March she took to Twitter, writing, "Who here actually thinks I would do 50 Shades of Grey as a movie? Like really. For real. In real life."
"Good. Well that's that sorted then," she wrote, adding a smiley face.
There has been similar excitement about the handsome, billionaire businessman Grey, who has a secret affinity for kinky sex. Rumors have swirled around stars like White Collar's Matt Bomer, Ian Somerhalder, Henry Cavill, Alex Pettyfer, Robert Pattinson and True Blood's Alexander Skarsgard.
The Lone Ranger's Armie Hammer told Playboy in June that he had discussed the part of Grey with his agent, but dismissed the notion quickly.
"I'm not going to sit on top of the laundry machine in spin cycle reading about putting a ball gag in someone's mouth. That doesn't do it for me," Hammer told the magazine.
As reaction to the announcement rolled in Monday, James took it all in stride.
"To all the supporters, lovers and haters - thank you so much for the passion that you have for this project," she tweeted. "You all rock. All of you."
Subsequent novels in the best-selling trilogy, Fifty Shades Darker and Fifty Shades Freed, explore the couple's deepening relationship. The books have been translated into 50 languages, and sold more than 70 million copies.
All three books will be made into movies by Universal Pictures and distributed by Focus Films.