Lecture 7 Flashcards
1
Q
Cell Signaling
A
- Extracellular signaling molecules: any molecule that can transmit signals between cells
- Receptor: Binds a signaling molecule
- Ligand: A signaling molecule that can be bound by a receptor
- Intracellular Signaling Molecules: any molecule that can transmit a signal within a cell
- Effectors: Receive signals to change cell behavior
2
Q
Signaling
A
- Contact dependent: two cells must be very close to connect membrane-bound signal in signaling cell to membrane-bound receptor in target cell
- Paracrine: Signaling cell releases diffusible signal to target cells
- Autocrine: A cell secretes a diffusible signal for itself
- Synaptic: Neuron extends an axon to reach distant target cell
- Endocrine: Endocrine cell secretes hormones into bloodstream for long range distribution
3
Q
GTP Binding Proteins
A
- GEFs: Helps exchange GDP for GTP
- GAPs: Activate GTPase activity to hydrolyze GTP to GDP
-GTP-binding turns signaling pathway on
4
Q
Signaling Speed
A
- Synaptic signaling is very fast
- Endocrine is slow
- Changes to transcription are slow
- Changes to protein function are fast
- Changes in membrane potential are fast
5
Q
Scaffold Proteins
A
- Bind intracellular signaling proteins
- Ensure signals passed in order
- Perception of signal modifies membrane lipids(phosphorylation of PIs)
- Intracellular signaling moelcules bind to new PIPs
6
Q
Protein Interaction
A
- SH3 domains bind proline rich sequences: do not require phosphorylation
- SH2 and PTB domains bind phosphorylated tyrosines
- PH domains bind PIs
- Coincidence detectors require multiple signals
