Mechanism for activation of the growth factor-activated AGC kinases by turn motif phosphorylation.

TY - JOUR

T1 - Mechanism for activation of the growth factor-activated AGC kinases by turn motif phosphorylation.

AU - Hauge, Camilla

AU - Antal, Torben L

AU - Hirschberg, Daniel

AU - Doehn, Ulrik

AU - Thorup, Katrine

AU - Idrissova, Leila

AU - Hansen, Klaus

AU - Jensen, Ole N

AU - Jørgensen, Thomas J

AU - Biondi, Ricardo M

AU - Frödin, Morten

N1 - Keywords: Amino Acid Motifs; Amino Acid Sequence; Binding Sites; Enzyme Activation; Humans; Hydrophobicity; Intercellular Signaling Peptides and Proteins; Models, Molecular; Molecular Sequence Data; Phosphorylation; Protein Structure, Secondary; Protein-Serine-Threonine Kinases; Signal Transduction

PY - 2007

Y1 - 2007

N2 - The growth factor/insulin-stimulated AGC kinases share an activation mechanism based on three phosphorylation sites. Of these, only the role of the activation loop phosphate in the kinase domain and the hydrophobic motif (HM) phosphate in a C-terminal tail region are well characterized. We investigated the role of the third, so-called turn motif phosphate, also located in the tail, in the AGC kinases PKB, S6K, RSK, MSK, PRK and PKC. We report cooperative action of the HM phosphate and the turn motif phosphate, because it binds a phosphoSer/Thr-binding site above the glycine-rich loop within the kinase domain, promoting zipper-like association of the tail with the kinase domain, serving to stabilize the HM in its kinase-activating binding site. We present a molecular model for allosteric activation of AGC kinases by the turn motif phosphate via HM-mediated stabilization of the alphaC helix. In S6K and MSK, the turn motif phosphate thereby also protects the HM from dephosphorylation. Our results suggest that the mechanism described is a key feature in activation of upto 26 human AGC kinases.

AB - The growth factor/insulin-stimulated AGC kinases share an activation mechanism based on three phosphorylation sites. Of these, only the role of the activation loop phosphate in the kinase domain and the hydrophobic motif (HM) phosphate in a C-terminal tail region are well characterized. We investigated the role of the third, so-called turn motif phosphate, also located in the tail, in the AGC kinases PKB, S6K, RSK, MSK, PRK and PKC. We report cooperative action of the HM phosphate and the turn motif phosphate, because it binds a phosphoSer/Thr-binding site above the glycine-rich loop within the kinase domain, promoting zipper-like association of the tail with the kinase domain, serving to stabilize the HM in its kinase-activating binding site. We present a molecular model for allosteric activation of AGC kinases by the turn motif phosphate via HM-mediated stabilization of the alphaC helix. In S6K and MSK, the turn motif phosphate thereby also protects the HM from dephosphorylation. Our results suggest that the mechanism described is a key feature in activation of upto 26 human AGC kinases.

U2 - 10.1038/sj.emboj.7601682

DO - 10.1038/sj.emboj.7601682

M3 - Journal article

C2 - 17446865

SN - 0261-4189

VL - 26

SP - 2251

EP - 2261

JO - EMBO Journal

JF - EMBO Journal

IS - 9

ER -