Role of Phosphorylation in cell signalling

Phosphorylation

A form of post-translational modification involving the addition of a phosphate group to proteins, often catalyzed by kinases, altering protein properties and being reversible.

Protein Kinases

Enzymes that catalyze the addition of phosphate groups to proteins, activating them as molecular switches.

Protein Phosphatases

Enzymes that catalyze the removal of phosphate groups from proteins, deactivating them.

Insulin Signalling

A process where insulin activates tyrosine kinase activity, leading to phosphorylation of target proteins like IRS, initiating major signaling pathways like PI3K, MAP kinase, and cAMP pathways.

Insulin Resistance

A condition where normal levels of insulin fail to activate metabolic actions, often linked to obesity and type 2 diabetes, involving serine kinases phosphorylating IRS proteins, negatively affecting insulin signaling.

Retinoblastoma (Rb) Protein

A protein whose phosphorylation status regulates cell cycle progression, with hypo-phosphorylation inhibiting E2F transcription factors and preventing cell cycle progression from G1 to S phase.