COOK pasta as directed on package, omitting salt.
MEANWHILE, add beans, tomatoes, broccoli, mushrooms and dressing to large skillet. Bring to boil; simmer on medium-low heat 5 min. or until vegetables are crisp-tender.
TOP with cheese; cover. Remove from heat. Let stand 2 to 3 min. or until melted. Drain pasta. Serve topped with sauce.