Absence/presence plots in a subset of 65 eukaryotic genomes. Animals and fungi have both TORC1 and TORC2 while plants have only TORC1 and ciliates have only TORC2. Apparently it is possible to lose either one of the complexes while maintaining the other. The GAP domain of TSC2 is well conserved and is found (with few exceptions) in species that also contain Rheb throughout the eukaryotic lineages. TSC1 is an animal/fungal invention and therefore newer than TSC2 and Rheb. The occurrence of TCTP in species lacking Rheb and vice versa, raises additional doubt on the debated Guanine Exchange Factor function of TCTP

Evolutionary reconstruction of the ancestral TOR signaling pathway based on the evolutionary reconstruction of the AGC kinase ancestral genes of S6K, RSK1, PKB and SGK1. a Simplified representation of the phylogenetic tree of the AGC kinases (see Figure S3). Species indication: Hs Homo sapiens, Sc S. cerevisiae, Sp S. pombe, At A. thaliana. b Reconstruction of TOR signaling in the animal ancestor. An AGC kinase duplicated in the ancestor of animals and choanoflagellates to give rise to PKB and SGK. SGK lost the ability to inhibit TSC2. New signaling inputs were invented in the animal ancestor, among which is the insulin signaling. c TOR signaling in the ancestor of animals and fungi. An AGC kinase duplicated in the ancestor of animals and fungi (Opisthokont ancestor) that give rise to S6K and RSK. The duplication was followed by subsequent sub-functionalization of ancestral functions between the two paralogs. d TOR signaling in LECA. The duplication of the ancestral AGC kinase that give rise to the RSK-S6K and PKB-SGK ancestral precursor genes corresponds to the differential activation by either TORC1 or TORC2, respectively. e Reconstruction of pre-LECA TOR signaling. The shared subunits TOR and LST8 of both TOR complexes suggest that before LECA there was at one point only one proto-TOR complex. As the AGC kinases also share single ancestry we can reduce the complexity of the TOR pathway in pre-LECA even further

Evolution of the mTOR pathway. We reconstructed the mTOR pathway based on literature. The indicated age of each gene is based on a reconstruction from phylogenetic profiles. For duplicate genes the outer circle denotes the time of duplication and the inner circle denotes the origin of the complete orthologous group. The regulation of TOR via insulin and TNFα are animal-specific additions onto an ancient TOR pathway. The invention of TSC1 in the animal and fungal ancestor allowed for new regulatory inputs onto TSC2. Duplications of an ancestral AGC kinase that gave rise to S6K, RSK, PKB and SGK played a significant role in the evolution of the TOR pathway