Soak maitake in warm water to cover for 10 minutes. Remove and set aside. Save soaking water for later use in soup stock.
Heat oil in a saucepan, sauté garlic, onions, and fresh mushrooms for 3 to 5 minutes. Add maitake, yellow summer squash, and zucchini, sauté 3 minutes. Add all other ingredients, except pasta, cover and simmer for 15 to 20 minutes over a medium-low heat.
While the sauce simmers, prepare pasta according to package directions and drain when done. Serve the hot marinara over the cooked pasta.
Per serving - 340 calories, 7 g fat (17% calories from fat), 14 g protein, 62 g carbohydrate, 13 g fiber, 0 mg cholesterol, 362 mg sodium