Booboo Stewart, of The Twilight Saga: Eclipse movie in theaters June 30, left, makes a muscle to make a difference for 13-year-old Sierra Lewis of Eloy, Ariz.

TUCSON, Ariz. — Booboo Stewart, who stars in The Twilight Saga: Eclipse movie being released June 30, has accepted a new role as a Muscular Dystrophy Association Celebrity Ambassador. The 16-year-old actor, singer, dancer, model and martial artist recently taped a variety of public service announcements and special appeals to help advance MDA's lifesaving mission.

View Booboo Stewart's 15 second and 30 second public service announcements for MDA’s new Muscle Team campaign (save to your desktop for optimal viewing).

MDA Celebrity Ambassadors include actors, musicians and other artists who use their talents to spread awareness of MDA’s unparalleled research and service programs.

Stewart, who is also a member of the MDA Muscle Team, will appear in a print PSA campaign for newspapers, magazines and websites beginning in July 2010. Other MDA Muscle Team members include Alison Sweeney, host of NBC's The Biggest Loser; Kurt Warner, former NFL quarterback; Wynonna Judd, country recording artist; Ace Young, American Idol finalist; Brandon Barash, a star of ABC's General Hospital; and Gold Medal Olympians Bart Conner and Nadia Comaneci.

"We’re very grateful that Booboo is lending his time and talents to help in the battle against muscular dystrophy," said Gerald C. Weinberg, MDA president & CEO. "As Seth Clearwater in The Twilight Saga: Eclipse, Booboo is already bringing his fans and new volunteers to MDA. We're truly blessed to have such an articulate and caring role model as a champion for our programs."

Stewart, who will be in three more movies being released this year (Logan; Dark Games; and Smitty) has appeared on TV's CSI Miami and ER; toured with The Jonas Brothers and Miley Cyrus; won a World Martial Arts Championship two years in a row and is in the Martial Arts Junior Hall of Fame. Frequently spotlighted in teen magazines and the entertainment press, Stewart is a member of the GATE program for the academically gifted and is working on a CD with 5 new songs.

“My family places a real priority on helping others,” said Stewart. “My father, Nils, and I recently had an opportunity to meet some of the outstanding young people served by MDA. I’m so glad we had that opportunity. Not only did we have fun together, but I learned how much the Association means to them and their families, which motivated me to help even more."

As a celebrity ambassador, Stewart will perform and speak at MDA events and fundraisers, participate in media interviews and address gatherings of MDA national sponsors.

MDA is the nonprofit health agency dedicated to finding treatment and cures for muscular dystrophy, amyotrophic lateral sclerosis (ALS) and related diseases by funding worldwide research. The Association, which was the first nonprofit organization to receive a Lifetime Achievement Award from the American Medical Association (“for significant and lasting contributions to the health and welfare of humanity”), also provides comprehensive health care and support services, advocacy and education.