Gβ4γ1 as a modulator of M3 muscarinic receptor signalling and novel roles of Gβ1 subunits in the modulation of cellular signalling.
Much is known about the how Gβγ subunits regulate effectors in response to G protein-coupled receptor stimulation. However, there is still a lot we don't know about how specific combinations of Gβ and Gγ are wired into different signalling pathways. Here, using an siRNA screen for different Gβ and Gγ subunits, we examined an endogenous M3 muscarinic receptor signalling pathway in HEK 293 cells. We observed that Gβ(4) subunits were critical for calcium signalling and a downstream surrogate measured as ERK1/2 MAP kinase activity. A number of Gγ subunits could partner with Gβ(4) but the best coupling was seen via Gβ(4)γ(1). Intriguingly, knocking down Gβ(1) actually increased signalling through the M3-mAChR most likely via an increase in Gβ(4) levels. We noted that Gβ(1) occupies the promoter of Gβ(4) and may participate in maturation of its mRNA. This highlights a new role for Gβγ signalling beyond their canonical roles in cellular signalling.
Department of Pharmacology and Therapeutics, McGill University, Montréal, Québec H3G 1Y6, Canada.
Shahriar M
SM
Khan
Department of Pharmacology and Therapeutics, McGill University, Montréal, Québec H3G 1Y6, Canada.
Adam
A
Min
Department of Pharmacology and Therapeutics, McGill University, Montréal, Québec H3G 1Y6, Canada.
Sarah
S
Gora
Department of Pharmacology and Therapeutics, McGill University, Montréal, Québec H3G 1Y6, Canada.
Geeda M
GM
Houranieh
Department of Pharmacology and Therapeutics, McGill University, Montréal, Québec H3G 1Y6, Canada.
Rhiannon
R
Campden
Leslie Dan Faculty of Pharmacy, University of Toronto, Toronto, Ontario M5S 3M2, Canada.
Mélanie
M
Robitaille
Department of Pharmacology and Therapeutics, McGill University, Montréal, Québec H3G 1Y6, Canada.
Phan
P
Trieu
Department of Pharmacology and Therapeutics, McGill University, Montréal, Québec H3G 1Y6, Canada.
Darlaine
D
Pétrin
Integrated DNA Technologies, Inc., Coralville, IA 52241, United States.
Ashley M
AM
Jacobi
Integrated DNA Technologies, Inc., Coralville, IA 52241, United States.
Mark A
MA
Behlke
Leslie Dan Faculty of Pharmacy, University of Toronto, Toronto, Ontario M5S 3M2, Canada.
Stéphane
S
Angers
Department of Pharmacology and Therapeutics, McGill University, Montréal, Québec H3G 1Y6, Canada. Electronic address: terence.hebert@mcgill.ca.
Terence E
TE
Hébert
D001665:Binding Sites; D020013:Calcium Signaling; D002217:Carbachol / Q000494:pharmacology; D018679:Cholinergic Agonists / Q000494:pharmacology; D004305:Dose-Response Relationship, Drug; D044387:GTP-Binding Protein beta Subunits / Q000235:genetics / Q000378:metabolism*; D044388:GTP-Binding Protein gamma Subunits / Q000235:genetics / Q000378:metabolism*; D005786:Gene Expression Regulation; D057809:HEK293 Cells; D006801:Humans; D020935:MAP Kinase Signaling System; D019950:Mitogen-Activated Protein Kinase 1 / Q000378:metabolism; D048052:Mitogen-Activated Protein Kinase 3 / Q000378:metabolism; D011401:Promoter Regions, Genetic; D055503:Protein Multimerization; D034622:RNA Interference; D012333:RNA, Messenger / Q000378:metabolism; D043587:Receptor, Muscarinic M3; D011976:Receptors, Muscarinic / Q000187:drug effects / Q000235:genetics / Q000378:metabolism*; D015398:Signal Transduction / Q000187:drug effects; D014158:Transcription, Genetic; D014162:Transfection
C000595896:CHRM3 protein, human; D018679:Cholinergic Agonists; C516790:GNB1 protein, human; C534984:GNB4 protein, human; D044387:GTP-Binding Protein beta Subunits; D044388:GTP-Binding Protein gamma Subunits; D012333:RNA, Messenger; D043587:Receptor, Muscarinic M3; D011976:Receptors, Muscarinic; D002217:Carbachol; C535150:MAPK1 protein, human; D019950:Mitogen-Activated Protein Kinase 1; D048052:Mitogen-Activated Protein Kinase 3
Co-transcriptional regulation; G protein-coupled receptors; G proteins; Gβγ Signalling; RNA interference screen; Signalling specificity