GCSP research stipend | Summer 2021

CK2 Phosphorylation of Tom22: Conserved or Convergently Evolved?

The translocase of the outer mitochondrial membrane (TOM) complex is the gateway into mitochondria. Phosphorylation of the receptor, Tom22, by the kinases CK1 and CK2 in both animals and fungi control mitochondrial biogenesis and mitophagy. However, whether phosphorylation of Tom22 proteins is widespread across eukaryotes is unclear. In this project, researchers used MUSCLE, HMMER, and NetPhos to predict CK1, CK2, and PKA phosphosites in Tom22 proteins from across eukaryote diversity. While N-terminal acidic extensions were found to only be present in animals and fungi, Tom22 is likely phosphorylated in every major eukaryotic group at N-terminally located serine or threonine residues.