Flashcards in Signal Transduction Deck (6)
1. Provide examples of four types of signaling systems in the body
● Contact dependent - immune cells must contact
○ Example → immune cells
● Paracrine- wound healing cell signals close by
○ Example 1→ regulate inflammation at infection site.
● Synaptic- neurotransmitters transmit via synapse
○ Example → neurotransmitters
● Endocrine- hormone cells signal to other cells far away
○ example→ hormones
2. Describe the changes that occur in some proteins (modifications, nucleotide binding, conformational changes) that allow them to act as molecular switches.
a. Proteins act as molecular switches that converting them from an inactive (non-signaling) form to an active (signaling)
i. upstream signal induces change to enable downstream signaling
3. Be able to sketch a generic signal transduction pathway that includes a receptor, intracellular signaling proteins, and effector proteins.
see sheet for pathway:
4. Describe the molecular aspects of signaling complexes and common interaction domains, and how they provide speed and specificity in signal transduction.
a. Types of Receptors
i. Ligand-gated ion channels
2. Ex: nicotinic ACh receptor
ii. Enzyme-coupled receptor
1. Receptor Tyrosine Kinase & SER/THR Kinases
2. Seconds to minutes
3. Ex: insulin receptor
iii. GPCRs - G Protein Coupled Receptors
1. Seconds to minutes
2. Ex: beta-adrenergic receptor
b. Interaction Domains
i. SH2 → SRC Homology 2: binds phosphotyrosine
ii. SH3 → SRC Homology 3: binds protein rich domains
iii. PTB → phosphotyrosine binding
iv. PH → Pleckstrin homology; binds phosphatidylinositol
5. Recognize the types of molecular signals (steroid) that are ligands of nuclear receptors.
● Nuclear receptors are ligand modulated proteins
● Respond to steroid hormones: cholesterol
○ Cholesterol is a major component of cell membranes,
○ hydrophobic and need carrier proteins to transport.
○ Small hydrophobic hormones can cross the membrane and then interact w/ intracellular receptors.
● respond to intracellular signals - peroxisome.