BIOL230W Week 7 Detailed Notes

BIOL230W Week 7 Day 1-3 Notes

Signaling Process Overview: Understand how signaling occurs, including key components such as signals, receptors, second messengers, and effector proteins.
Protein Conformation Changes: Define how changes in the conformation of proteins lead to variations in their functions, impacting signaling pathways.
Receptor Comparison: Compare and contrast characteristics of G-protein coupled receptors (GPCRs), Receptor Tyrosine Kinases (RTKs), and intracellular androgen receptors.
GPCR Characteristics: Identify the major features of GPCRs, such as the seven transmembrane regions, ligand binding sites, and G-protein interaction regions.
Domains and Motifs: Explain differences between domains, structural motifs, and peptide motifs in the context of proteins.
Use of Legends: Apply legends to integrate and interpret information regarding protein functions.

Signal (ligand): A chemical that elicits a cellular response.
Receptor: Proteins that detect signals and initiate transmission of the signal.
Conformation Change: Structural modification in proteins that alters function.
GPCR: G-protein Coupled Receptor; integral membrane protein involved in signal transduction.
Peptide Motif: Specific sequences in proteins critical for their function.

Signal: Can arise from environmental or cellular sources, including proteins, hormones, and growth factors.
Receptor Function: Integral proteins that sense and respond to signals, causing conformational changes upon binding.
Signal Transduction: The process of relaying a signal through a cell involves the alteration of effector proteins, often mediated by secondary messengers.
Final Effector: The last modulated protein in the pathway, often leading to changes in physiological responses or gene expression.

Signals: Various ligands from environmental or cellular origins.
Receptors: Proteins that detect and bind signals, leading to their activation.
Transduction: The process of transmitting signals inside the cell, often involving secondary messengers.
Effectors: Proteins that execute downstream effects, resulting in a cellular response.
Physiological Changes: Changes that occur at the cellular level, potentially impacting gene expression and cellular behavior.

Structure: Integral membrane proteins with extracellular ligand-binding domains and intracellular G-protein interaction domains.
G-Proteins: Composed of three subunits and play a key role in signal transduction upon receptor activation (conformation change from ligand binding).

Activate through ligand binding, leading to dimerization and autophosphorylation of tyrosines, enabling signal transduction through downstream effectors.

Ligand binding induces specific changes in receptor conformation, which is essential for the transmission of the signaling cascade.

cAMP (Cyclic Adenosine Monophosphate): Commonly associated with GPCRs, synthesized from ATP through adenylyl cyclase.
DAG (Diacylglycerol) and IP3 (Inositol trisphosphate): Derived from membrane phospholipids, involved in further signaling cascades, specifically in calcium release.
Calcium Ions (Ca²⁺): Act as secondary messengers that can modulate various cellular activities.

Kinases: Enzymes that add phosphate groups to proteins, often activating or inactivating them.
Phosphatases: Remove phosphate groups, counteracting the actions of kinases and helping to regulate signaling pathways.

The last modified protein in a signaling pathway, can lead to gene expression changes or physiological responses (e.g., metabolism regulation).

Upstream Events: Early steps in the signaling process.
Downstream Events: Later responses that occur following the initial signal detection and transduction.

Inflammation Pathway: Investigate the effects of blocking certain enzymes or proteins in a pathway.
Hippo Pathway: Understanding growth regulation at a genetic level through signaling inhibition or enhancement.