Cell Signaling Fundamentals

📋 Course Outline

1. Principles of Cell Signaling
2. Extracellular Signal Types
3. Cell Surface Receptor Classes
4. Signal Transduction Process
5. Intracellular Signaling Proteins
6. Signal Amplification and Modulation
7. G Protein-Coupled Receptors
8. Second Messenger Pathways
9. Receptor-Mediated Responses

📖 1. Principles of Cell Signaling

🔑 Key Concepts & Definitions

• Signals can act over long or short range: Cell signaling involves communication through signals that can diffuse across large distances (e.g., hormones in blood) or operate locally (e.g., contact-dependent signals).
• Limited extracellular signals can produce diverse cell behaviors: A small set of extracellular signals can elicit a variety of responses depending on the cell type and context, often through combinations of signals and intracellular pathways.
• Cell responses to signals can be fast or slow: The speed of cellular response varies; some responses, like muscle contraction, occur within milliseconds, while others, such as gene expression changes, take hours.
• Cell-surface receptors relay signals via intracellular pathways: Receptors on the cell surface detect extracellular signals and activate intracellular signaling pathways that transmit the message inside the cell.
• Intracellular signaling proteins act as molecular switches: These proteins cycle between active and inactive states, often through GTP/GDP binding, to propagate and regulate signals…