Transduction Systems for Peptide Hormones, Growth Factors, and Cytokines
Signal Transduction Overview: Signal transduction refers to the process by which cells respond to external signals (such as hormones, growth factors, and cytokines) and convert these signals into specific cellular responses. This process usually involves the activation of a series of proteins within the cell, leading to changes in gene expression, enzyme activity, or cellular behaviour.
Transduction Systems for Peptide Hormones, Growth Factors, and Cytokines
Key Molecules:
- Peptide Hormones: Short chains of amino acids that regulate various physiological functions (e.g., insulin, glucagon).
- Growth Factors: Proteins that promote cell growth, proliferation, and differentiation (e.g., Epidermal Growth Factor (EGF)).
- Cytokines: Small proteins involved in cell signalling, particularly in the immune response (e.g., interleukins, interferons).
Transduction Systems for Peptide Hormones, Growth Factors, and Cytokines
Receptors: These molecules interact with specific receptors on the cell surface:
- G-Protein Coupled Receptors (GPCRs): Activate G-proteins that trigger various intracellular signalling cascades.
- Receptor Tyrosine Kinases (RTKs): Undergo autophosphorylation upon ligand binding, initiating a cascade of downstream signalling events.
Mitogen-Activated Protein Kinase (MAPK) Cascade
Overview: The MAPK cascade is a key signalling pathway that transmits signals from the cell surface to the nucleus, promoting cellular responses such as proliferation, differentiation, and survival. It is one of the most well-studied mitogenic (cell division-inducing) pathways.