Chap 11 - Cell communication Flashcards
Transduction
Relaying the signal from receptors to the proteins that create a cellular response.
Three major types of cell surface trans-membrane receptors
In animals
- GCPRs
- RTKs
- Ion channel receptors
G-protein
Proteins that bind with GTP (instead of ATP)
GCPR function
G-Coupled Protein Receptor
Activates a G-protein (attaches a GTP) when receiving stimulus.
GPCR structure
Seven transmembrane a helices.
Binding sites between the helices, both inside and outside the cell.
Protein kinase
Enzymes that attach a phosphate from ATP onto proteins.
RTK function
Receptor Tyrosine Kinases.
Phosphorylises amino acid tyrosine.
Proteins in cytoplasm are activated by the tyrosines.
RTK structure
Two monomers with a long tail are located near eachother; tyrosines attached on the tails.
Dimerisation
Two RTKs forming a dimer complex when they both receive a signal.
Ion channel receptors’ other name
Ligand-gated channel
Type of cell surface receptor associated with cancer
RTKs
Intracellular receptor function
Usually activates a transcription factor that controls gene activation.
Location of intracellular receptors
Cytoplasm or inside nucleus - often just proteins floating around.
Phosphatases
Enzymes catalyzing the removal of phosphate from proteins.
Role of phosphatases in signal transduction
Deactivates relay proteins so that the signal can be switched off quickly.
