L14 General Principles of Cell Signalling Flashcards
Cell signalling is the transfer of information from…
Cell to cell and from environment to cell
Cell signalling results in the control of…
Cell behaviour
Cell communicate via…
Signalling pathways
The basic components of a signalling pathway are (5)…
- Signal (ligand)
- Reception (ligand binds to receptor)
- Transduction (signal converted)
- Amplification (signal increased)
- Response
The activity of signalling pathways can be adjusted by (2)…
- Changing the level of the signalling proteins (SLOW 🐌)
* Modifying the existing proteins (through conformational changes or phosphorylation) (FAST 🐇)
The signals in a signalling pathway can be…
Physical or chemical
Most signals are…
Chemical
On average, what percentage of eukaryotic genomes codes for signalling molecules?
10-15%
Gap Junction signalling
- Occurs over shortest distance
- Fast (passive) diffusion of ions and small metabolites
- e.g. in heart muscle ❤️
Contact dependent signalling
- Signal cell makes contact with target cell
* Short distance (c2c contact required)
Paracrine signalling
- Medium distance (nearby cells)
- Diffuses via local mediators
- important during development
Autocrine signalling
- Medium distance
- Cell can bind to the same signal it secretes
- Signal binds to cells of the same type
Synaptic signalling
• Long distances (via nerves, see excitable cells lectures)
Endocrine signalling
• Paracrine signalling over long distances (i.e. through the bloodstream)
Receptors can be located on (2)…
- Cell surface (bind hydrophilic molecules)
* Intracellular (bind hydrophobic molecules)
