G proteins as drugs ( enzyme linked and intracellular receptors ) Flashcards
tyrosine kinase linked recepits are agonists and they phosphorylates —- on key signalling molecules for the activation of —-
- tyrosines
- cell signalling
intracellular receptors are agonist and they transport to —- and responsible for the activation of ——
- nucleas
- transcription and translation
ligand gated ion channels are agonists that deals w — and activates —-
-Na
- conductance
- G protein coupled receptors are agonist and the G protein activation causes the generation of —– which leads to activation of —-
- second messenger
- cell signalling
how does the receptor tyrosine kinase ( RTK) structure allow it to receive and transmit signals?
-extracellular domain : responsible for capturing or binding signals ( ligands )
- intacellular tyrosine kinase domain: responsible for transmitting signal when ligand bound
mechanism of action of receptor tyrosine kinase :
1. ligand —– , —— , and —
2. binding of —– to —-
- these —- proteins link — molecules together but they don’t —–
- growth receptor binding protein 2 is an —–
- one arm of Grb2 reconginizes a —-on active site ( SH2 domain )
- other arm recognises — on signalling molecules ( SH3 domain )
3. binding of — to active Ras
- —- is a g protein ( small GTPase ) required to transmits RTK cell signalling
- SoS acts to convert —- Ras into —- Ras by —- it and removing —–
- once this happens Ras binds to — and makes it —-
4. Ras —-
- active — triggers the activation of numerous cell signalling pathways which changes proteins — and —–
this leads to cell —-
- ligand binding
- dimerisation
- and autophorphorlation
- adapter protein
- active receptor
- adapter
- signalling
- they don’t signal
- adapter proteins
- phosphotryrosine
- proline
- RTK-Grb2-SoS
- Ras
- inactive
- active
- binding
- GDP
-GTP - active
- cell signalling
- Ras
- activity
- gene expression
- cell proliferation
how does ligand-gated ion channels linked receptors structure allow it to receive and transmits signals?
- ligand gated ion channels contain —- subunits around a —-
- has —–
- membrane receptor coupled directly to —-
- example:
- receptors
- central pore
- transmembrane spanning
- ion channel
- neurotransmitter
mechanism of action of ligand gated ion channel linked receptors:
1. — binds and channels —
-when a — binds to a receptor the channel — and activates a —- of ions
- —- of receptors and channel
- — response - hormones binding promots ion gates to open in —-
- hormone
- opens
- hormone
- opens
- influx
- direct coupling
- rapid
- milliseconds
stages of ion channel linked receptors activation summary
1. resting —>
2. activated —>
3. inactivated —->
- able to respond to ligand stimulus
- open to ion flux
- desensitised to stimulus
glucorticodes is an example of —
nuclear receptor
-in nuclear receptor , the ligand enters the cell to interact with its —
-recepor-ligand — throughout cell to interact directly w —-
- changes cell gene —-
- ligand
- translocates
- nucleas
- expression profile
how does the nuclear receptor structure allow it to receive and transmits signals ?
it contains :
a —- binding site to bind to ligand and chaperone
a — binding site to interact w defined sites in genome
- hormone
- dna
nuclear receptors mechanism of action:
1. —- ligand receptor binding
- — hormones enters via —-
- receptor in the —- bound to a molecular —-
- hormone binding to a receptor causes — of molecular chaperone
2. steroid complex can translocate to —-
- steroid hormone bound to a receptor can translocate to the — once the — is removed
3. — binding domain of steroid receptor complex binds to a specific —- region
- binds to — associated receptors to initiates —- programmes
4. generation of —- protein response
- the gene expression profile of cell changes due to initiation of —– programmes triggered by —
- intracellular
- steroid
- cell membrane
- cytosol
- dissociation
- nucleas
- nucleas
- chaperone
- dna
- genomic
- dna
- genomic
- dna
- gene expression
( info:
LBD: ligand binding domain
DBD: dna binding domain
AD: activation domain ) - anti-inflammatory
- transcriptional
- steriod receptor complex
