TD-60 (RCC2) structurally resembles a guanine nucleotide exchange factor (GEF), but its target GTPase was unknown. Here Papini et al.show that TD-60 is a GEF for RalA, and that RalA helps to regulate the chromosomal passenger complex and kinetochore–microtubule interactions in mitosis.
- Diana Papini
- Lars Langemeyer
- William C. Earnshaw