... Mst2. The mutation of K59R in the ATP-binding region of the Mst1 kinasedomain renders the kinase inactive [7 ,11 ,12 ,16 ], and byhomology with Mst1 the analogous mutation of K56R in Mst2 should also ... severalproteins. The growth inhibitory proteins, Rassf1 andNore1 can form complexes with and inhibit Mst1activity in an interaction involving their conservedC-termini [15 ,25]. Interestingly, while ... Mst1and Mst2 have been shown to interact with a numberor proteins, including the novel Ras effector 1, Nore1 [15 ,16 ], the putative tumour suppressor (Ras suppres-sor factor 1; Rassf1) [15 ,16 ,25],...