1. Department of Molecular and Integrative Physiology (S.P., Y.Z., S.Y., B.S.K.), University of Illinois at Urbana-Champaign, Urbana, Illinois 61801-3704
2. Department of Molecular and Cellular Biology (J.X., L.L., J.L., F.D., B.W.O.), Baylor College of Medicine, Houston, Texas 77030-3498