Bring large pot of water to a boil. When water boils add 1 teaspoons salt and pasta, stirring to prevent sticking. Cook, stirring occasionally, until al dente, about 10-15 minutes.
Meanwhile, steam green beans and squash seperately until each is just tender. Rinse under cold running water and drain well.
Drain pasta, rinse under cold running water and drain well. Transfer to large serving bowl. Add green beans, squash, artichokes with liquid, tomatoes, vinegar, oregano, cheese, salt and pepper. Toss to mix and coat. Serve at room temperature.