Cell signalling 1

What are the two main signalling methods?

Intercellular and intracellular

What are the forms of intercellular signalling?

Contact-dependent

Autocrine

Paracrine

Synaptic

Endocrine

What two forms can ligands take?

Agonists that promote a response

Antagonists that inhibit a response (prevent agonists binding)

What are the two domains of receptors?

Ligand-binding domain and an effector domain

What are the 4 major receptor types?

Ion channels

GPCR

Enzyme-coupled receptors

Nuclear receptors

What proteins are involved in addition/removing phosphates?

Protein kinase add

phosphatases remove

What molecules are involved in GTP/GDP transfer?

Guanine nucleotide exchange factors (GEFs) promote GDP loss and GTP addition

GTPase activating proteins (GAPs) increase rate of GTP hydrolysis

What are intracellular signalling complexes?

Signalling proteins are brought together which increases efficiency and speed

What is receptor desensitisation?

Sustained exposure to stimuli cause receptors to desensitise

Receptors can be put into endosomes - receptor sequestration

Broken down by lysosomes - receptor down-regulation

receptor inactivation

inactivation of signalling proteins

inhibitory proteins