About MOBKL / MOB1, Mps One Binder Kinase Activator:
MOB1 is a multifunctional protein best known for its integrative role in regulating metazoan Hippo and NDR pathway signaling and yeast Mitotic Exit Network signaling. Human MOB1 binds the upstream kinases MST1 and MST2 and the downstream AGC group kinases LATS1, LATS2, NDR1, and NDR2. MOB1 binds to MST1 and MST2 via its phosphopeptide-binding infrastructure, the specificity of which matches MST1 and MST2 phosphorylation consensus.
MOB1 binding to the LATS and NDR kinases, on the other hand, is mediated by a distinct interaction surface on MOB1. MOB1 facilitates the activation of downstream kinases by upstream kinases via a trans-phosphorylation event by assembling both upstream and downstream kinases into a single complex. MOB1 binding to its upstream partners also makes MOB1 a substrate, which allows it to regulate its two protein interaction activities differentially (at least in vitro). In addition to associating with MST1 (and MST2), previous interaction proteomics analysis revealed that MOB1A and MOB1B could associate in a phosphorylation-dependent manner with at least two other signaling complexes, one containing the Rho guanine exchange factors (DOCK6-8) and the other containing the serine/threonine phosphatase PP6.
MOB1, Mps One Binder Kinase Activator Structure
The MPS One Binder (MOB) 1 protein is an evolutionarily conserved eukaryotic protein family (with sizes ranging from 210–314 amino acids), the founding member discovered in yeast via interaction screens the kinase Mps1 and shown to be critical for mitotic exit. S. cerevisiae contains two yeast MOB proteins, Mob1 and Mob2. They act as AGC group kinase regulators, with Mob1 facilitating Dbf2 kinase activation in the Mitotic Exit Network pathway and Mob2 facilitating Cbk1 kinase activation in the RAM (regulation of Ace2 and morphogenesis) network pathway.