Basics of cell signalling Flashcards
what is cell signalling dependent on
specificity of proteins
ability of ligand-binding or covalent modification to induce conformational change
modulates activity/target specificity/protein levels- transcription/translation/stability
what are ligands
signalling molecules
what is a receptor protein
place a signal binds
what is a signal transduction pathway
converting the signal into a cellular response
what are the different ways a signal travels to its target
direct contact
paracrine signalling (autocrine)
endocrine signalling
synaptic signalling
direct contact
gap junctions provides the direct contact
paracrine/autocrine signalling
secretory cell with adjacent target cells
endocrine signalling
hormone secretion into the blood by the endocrine gland
synaptic signalling
nerve cell with a neurotransmitter
synaptic gap
then the target cell
what occurs in the cell after the signal arrives
there’s either a single response (glucagon)
or a variety of responses (adrenaline/epinephrine)
some use second messenger systems
two directions of phosphorylation
can act as an on/off switch for protein activity
can activate/deactivate proteins in signal transduction pathways
components of ATP
adenine
ribose
3 phosphates
protein kinase
enzyme that takes phosphate from ATP and phosphorylates a protein
protein phosphatase
reverse the process of a kinase (dephosphorylates proteins)
what are the three super families of cell surface receptors
chemically gated ion channels
enzymatic receptors
G-protein coupled receptors
