Plays a role in regulation of adenylate cyclase and protein kinase B (PKB) activation during aggregation. Involved in both chemotaxis and signal relay. Part of a complex, TORC1, consisting of tor, raptor and lst8. Part of a complex, TORC2, consisting of tor, lst8, piaA and ripA. Additional proteins, such as 14-3-3 and heat-shock proteins, may also belong to the TORC2 complex. Cells have serious developmental defects, because they are unable to activate the aggregation-stage adenylyl cyclase acaA in response to chemoattractant and are defective in chemotaxis. Belongs to the WD repeat LST8 family.