- The molecular heterogeneity of the smg-21/Krev-1/rap1 proteins, a GTP-binding protein having the same effector domain as ras p21s, in bovine aortic smooth muscle membranes. Kawata, M., Kawahara, Y., Sunako, M., Araki, S., Koide, M., Tsuda, T., Fukuzaki, H., Takai, Y. Oncogene (1991)