Week 2 - Recap and Quiz Flashcards
What type of receptor do adrenaline/noradrenaline ligands bind to?
Cell Surface GPCRs
Which adrenergic receptor is responsible for mediating the broncho-dilatory effects of adrenaline
b2 adrenergic receptor
in respiratory tract smooth muscle cells, which heterotrimeric G protein complex does this receptor couple to?
Gs
What membrane-associated effector does this heterotrimeric G protein complex regulate?
Andenylyl cyclase
Intracellular levels of what second messenger are regulated by this effector
cAMP (levels increase)
What ‘downstream’ signalling molecule is activated as a consequence?
Protein Kinase A
How does activated PKA cause the broncho-dilatory effect of adrenaline?
Inhibits MLCK
Which adrenergic receptor is responsible for mediating the vasoconstrictive effects of adrenaline?
a1 adrenergic receptor
In the vasculature, smooth muscle a1 adrenergic receptors couple to which heterotrimeric G protein complex
Gq
What membrane-associated effector does this heterotrimeric G protein complex regulate
Phospholipase C
Intracellular levels of what second messenger are regulated by the effector phospholipase C?
IP3 and DAG (levels increase)
Ca2+ (levels increase)
What ‘downstream’ signalling molecule is activated as a consequence of IP3, DAG and Ca2+ levels increasing?
CRAC
Protein Kinase C
If expression of a MAPKKK enzyme is lost due to homozygous mutation (that introduces a premature STOP codon) in the relevant MAPKKK gene:
MAPK cannot be activated regardless of the presence of ligand.
Of the following second messengers which one(s) are hydrophobic?
_________rely on _________ such as Ca2+, cAMP and DAG to activate or inactivate a variety of pathways within the cell
Place the following events in the correct order as they occur after the dissociation of Gα/β/γ complexes:
cAMP is produced
phosphate groups are attached to serine/threonine residues
cAMP binds to a protein kinase
phosphodiesterases breakdown cAMP
Gα binds to adenylyl cyclase
The enzyme that catalyzes the hydrolysis of PI(4,5)P2 into two second messenger molecules, is called:
The addition of a (PO4)3- group to a protein is a common form of protein modification. This chemical modification is called ________.
In the MAPK signalling pathway, protein phosphorylation serves to ________?
- Activate the next component in the signalling pathway
- Amplify the original signal as it is transmitted through the signalling pathway
Which of the following are the most commonly phosphorylated amino acids in mammals?
A signal peptide:
May be responsible for targeting the protein to the Golgi
Ubiquitin is added to:
The side chain of Lysine residues on the target protein via an amide bond
Some mitogen receptors activate a protein kinase cascade, which includes the participation of multiple enzymes, to effect a change in gene expression. Which of the following statements about a protein kinase cascade are true?
protein kinase cascades are important components of membrane signalling. The signal is amplified, target proteins for kinases determine responses, and mutations in signalling pathways are a significant part of cancer cell growth
