Conserved yet flexible

29 Nov 2011

In eukaryotic growth, a major regulatory role is played by the protein TOR (target of rapamycin). TOR is a kinase - a protein that phosphorylates other proteins - and is part of two protein complexes called TORC1 and TORC2. Both complexes are components of important pathways: TORC1 is activated by the insulin signalling pathway and TORC2 regulates cytoskeleton rearrangement in response to growth. Dysfunction of TOR or other components in TOR pathways is linked to cancer development. Although TOR has been characterised in animals, fungi and plants, not all of the TOR complex subunits or pathway components have been equally conserved. To study the evolution of the TOR pathway, John van Dam and colleagues at Utrecht University, performed phylogenetic analyses on the components of the TOR pathway. They found that TOR, the subunits of the two TOR complexes and a large part of the pathway components form an evolutionary core, while other regulatory inputs have been added to the pathway during evolution. According to van Dam et al., their results show that a highly conserved pathway can also be flexible.

TJP van Dam, FJT Zwartkruis, JL Bos, B Snel
Evolution of the TOR pathway
Journal of Molecular Evolution, published online 5 November 2011

By: Esther Thole