Mechanism of adrenergic Ca1.2 stimulation revealed by proximity proteomics.

TitleMechanism of adrenergic Ca1.2 stimulation revealed by proximity proteomics.
Publication TypeJournal Article
Year of Publication2020
AuthorsLiu, G, Papa, A, Katchman, AN, Zakharov, SI, Roybal, D, Hennessey, JA, Kushner, J, Yang, L, Chen, B-X, Kushnir, A, Dangas, K, Gygi, SP, Pitt, GS, Colecraft, HM, Ben-Johny, M, Kalocsay, M, Marx, SO
JournalNature
Volume577
Issue7792
Pagination695-700
Date Published2020 01
ISSN1476-4687
Abstract

Increased cardiac contractility during the fight-or-flight response is caused by β-adrenergic augmentation of Ca1.2 voltage-gated calcium channels. However, this augmentation persists in transgenic murine hearts expressing mutant Ca1.2 α and β subunits that can no longer be phosphorylated by protein kinase A-an essential downstream mediator of β-adrenergic signalling-suggesting that non-channel factors are also required. Here we identify the mechanism by which β-adrenergic agonists stimulate voltage-gated calcium channels. We express α or β subunits conjugated to ascorbate peroxidase in mouse hearts, and use multiplexed quantitative proteomics to track hundreds of proteins in the proximity of Ca1.2. We observe that the calcium-channel inhibitor Rad, a monomeric G protein, is enriched in the Ca1.2 microenvironment but is depleted during β-adrenergic stimulation. Phosphorylation by protein kinase A of specific serine residues on Rad decreases its affinity for β subunits and relieves constitutive inhibition of Ca1.2, observed as an increase in channel open probability. Expression of Rad or its homologue Rem in HEK293T cells also imparts stimulation of Ca1.3 and Ca2.2 by protein kinase A, revealing an evolutionarily conserved mechanism that confers adrenergic modulation upon voltage-gated calcium channels.

DOI10.1038/s41586-020-1947-z
Alternate JournalNature
PubMed ID31969708
PubMed Central IDPMC7018383
Grant ListT32 HL120826 / HL / NHLBI NIH HHS / United States
R01 HL113136 / HL / NHLBI NIH HHS / United States
R01 HL126735 / HL / NHLBI NIH HHS / United States
R01 HL146149 / HL / NHLBI NIH HHS / United States
P30 CA013696 / CA / NCI NIH HHS / United States
T32 HL007343 / HL / NHLBI NIH HHS / United States
R01 HL121253 / HL / NHLBI NIH HHS / United States
T32 HL007854 / HL / NHLBI NIH HHS / United States
UL1 TR001873 / TR / NCATS NIH HHS / United States
R01 HL140934 / HL / NHLBI NIH HHS / United States
F31 HL142178 / HL / NHLBI NIH HHS / United States