Deciphering the Structural Basis of Eukaryotic Protein Kinase Regulation

• Published in: PLoS biology Vol. 11; no. 10; p. e1001680
• Main Authors: Meharena, Hiruy S., Chang, Philip, Keshwani, Malik M., Oruganty, Krishnadev, Nene, Aishwarya K., Kannan, Natarajan, Taylor, Susan S., Kornev, Alexandr P.
• Format: Journal Article
• Language: English
• Published: United States Public Library of Science 01.10.2013; Public Library of Science (PLoS)
• Subjects: Amino Acid Motifs; Amino Acids - metabolism; Biocatalysis; Databases, Protein; Diabetes; Enzyme Activation; Eukaryota - enzymology; Experiments; Health aspects; Hydrophobic and Hydrophilic Interactions; Kinases; Models, Molecular; Phosphorylation; Physiological aspects; Protein binding; Protein kinases; Protein Kinases - chemistry; Protein Kinases - metabolism; Sequence Alignment; Structure-Activity Relationship; United States; Phosphorylation; Sequence Alignment; Biocatalysis; Eukaryota; Protein Kinases; Hydrophobic & Hydrophilic Interactions; Databases, Protein; Models, Molecular; Structure-Activity Relationship; Enzyme Activation; Amino Acids; Amino Acid Motifs
• ISSN: 1545-7885; 1544-9173; 1545-7885
• DOI: 10.1371/journal.pbio.1001680

Eukaryotic protein kinases (EPKs) regulate numerous signaling processes by phosphorylating targeted substrates through the highly conserved catalytic domain. Our previous computational studies proposed a model stating that a properly assembled nonlinear motif termed the Regulatory (R) spine is essential for catalytic activity of EPKs. Here we define the required intramolecular interactions and biochemical properties of the R-spine and the newly identified "Shell" that surrounds the R-spine using site-directed mutagenesis and various in vitro phosphoryl transfer assays using cyclic AMP-dependent protein kinase as a representative of the entire kinome. Analysis of the 172 available Apo EPK structures in the protein data bank (PDB) revealed four unique structural conformations of the R-spine that correspond with catalytic inactivation of various EPKs. Elucidating the molecular entities required for the catalytic activation of EPKs and the identification of these inactive conformations opens new avenues for the design of efficient therapeutic EPK inhibitors.