Biochemical Journal Young Investigator Award winner

John Steichen

John Steichen is a second-year graduate student in the laboratory of Dr Susan Taylor at the University of California - San Diego. He has been studying the activation of protein kinase A by phosphorylation of a threonine residue in a region called the activation loop. He believes PKA can serve as a model for the activation of the AGC family of protein kinases due to the conservation of the phosphorylation site. He has characterized the dynamics of PKA in active and inactive states by hydrogen deuterium exchange and found the enzyme is highly flexible in solution but becomes locked into an active conformation once phosphorylated on its activation loop. Additionally, a peptide at the C-terminus of the activation loop is protected from solvent in the active state but is solvent-accessible in the inactive state which exposes the critical threonine residue to phosphorylation by another kinase. In the future he will also be studying the activation of PKA by another AGC kinase called PDK1 as well as solving the structure of PKA in its unphosphorylated state.