Capillary Isoelectric Focusing of Akt Isoforms Identifies Highly Dynamic Phosphorylation in Neuronal Cells and Brain Tissue

摘要: The PI3K/PTEN/Akt pathway has been established as a core signaling that is crucial for the integration of neurons into neuronal circuits and maintenance architecture function in adult brain. Akt1–3 kinases are specifically activated by two phosphorylation events on residues Thr308 Ser473 upon growth factor signaling, which subsequently phosphorylate vast cohort downstream targets. However, we still lack clear understanding complexity regulation isoform specificity within pathway. We utilized capillary-based isoelectric focusing method to study dynamics Akt cells developing brain identify previously undescribed features activation. First, show accumulation multiple forms occur concurrently with acute PI3K activation provide evidence uncoupling phosphorylation, well differential sensitivities Akt1 inhibition. Second, detect transient shift pattern during early postnatal development, at stages corresponding synapse development maturation. Third, Ser473-Akt species PTEN deletion mature neurons, suggests inherent differences pools accessible factors compared controlled PTEN. Our demonstrates presence complex time- signal-dependent manner neurons.