- An alternative transcript derived from the trio locus encodes a guanosine nucleotide exchange factor with mouse cell-transforming potential. Yoshizuka, N., Moriuchi, R., Mori, T., Yamada, K., Hasegawa, S., Maeda, T., Shimada, T., Yamada, Y., Kamihira, S., Tomonaga, M., Katamine, S. J. Biol. Chem. (2004)