Intracellular Kinases in the Akt Pathway

Protein kinases transfer phosphate groups from ATP to serine, threonine, or tyrosine residues on protein/peptide substrates, directly affecting the activity and function of the target. Radiolabel studies suggest that approximately 30% of proteins in eukaryotic cells are subject to phosphorylation. Lipid kinases, such as the PI 3-Kinase and DGK families, transfer phosphate groups to lipid substrates, which can then act as docking sites and second messengers for downstream signaling proteins. Kinase activation regulates a broad range of cellular activities including the cell cycle, differentiation, metabolism, and neuronal communication. The intracellular kinases listed below are associated with the Akt signaling pathway, which regulates cell growth, survival, proliferation, autophagy, and metabolism. Unregulated kinase signaling can be oncogenic and components of the Akt pathway are often altered in cancer.