DHHC5 Mediates β-Adrenergic Signaling in Cardiomyocytes by Targeting Gα Proteins

Abstract

S-palmitoylation is a reversible posttranslational modification that plays an important role in regulating protein localization, trafficking, and stability. Recent studies have shown that some proteins undergo extremely rapid palmitoylation/depalmitoylation cycles after cellular stimulation supporting a direct signaling role for this posttranslational modification. Here, we investigated whether β -adrenergic stimulation of cardiomyocytes led to stimulus-dependent palmitoylation of downstream signaling proteins. We found that β -adrenergic stimulation led to rapidly increased G α s and G α i palmitoylation. The kinetics of palmitoylation was temporally consistent with the downstream production of cAMP and contractile responses. We identified the plasma membrane-localized palmitoyl acyltransferase DHHC5 as an important mediator of the stimulus-dependent palmitoylation in cardiomyocytes. Knockdown of DHHC5 showed that this enzyme is necessary for palmitoylation of G α s, G α i, and functional responses downstream of β -adrenergic stimulation. A palmitoylation assay with purified components revealed that G α s and G α i are direct substrates of DHHC5. Finally, we provided evidence that the C-terminal tail of DHHC5 can be palmitoylated in response to stimulation and such modification is important for its dynamic localization and function in the plasma membrane. Our results reveal that DHHC5 is a central regulator of signaling downstream of β -adrenergic receptors in cardiomyocytes.

Regulatory effects of post-translational modifications on zDHHC S-acyltransferases

“…Several recent studies have shown that the C-terminal S -acylated cysteines in zDHHC5 ( Fig. 2 ) are important in regulating the distribution of this enzyme between the plasma membrane and internal membranes in nonneuronal cells ( 85 – 87 ). Indeed, one study reported that S -acylation of these cysteines occurred in response to isoproterenol stimulation, leading to stabilization of zDHHC5 at the plasma membrane ( 85 ).…”

“…2 ) are important in regulating the distribution of this enzyme between the plasma membrane and internal membranes in nonneuronal cells ( 85 – 87 ). Indeed, one study reported that S -acylation of these cysteines occurred in response to isoproterenol stimulation, leading to stabilization of zDHHC5 at the plasma membrane ( 85 ). As the C-tail of zDHHC5 is also S -acylated in brain, it will be interesting in future work to investigate the interplay between S -acylation and phosphorylation of the YDNL endocytic motif in regulating activity-dependent trafficking of this enzyme in neurons.…”

Integrated network pharmacology and molecular docking approaches to reveal the synergistic mechanism of multiple components in Venenum Bufonis for ameliorating heart failure

“…Among them, the best described is the mechanism mediated by β -adrenergic receptor ( β -AR)–Gs–adenylate cyclase (AC) pathway ( Baker, 2014 ). Activation of β -AR–Gs–AC plays an important role in increasing heart rate and force of myocardial contraction ( Chen et al, 2020 ; Santulli & Iaccarino, 2016 ). According to our predicted results, VB could regulate β -AR–Gs–AC pathway by targeting Gs (GNAS) and AC (ADCY2 and ADCY5).…”

Calcium-dependent protein acyltransferase DHHC21 controls activation of CD4+T cells

“…Extremely rapid (within minutes) increase of protein S-acylation in response to agonist stimulation has been recently observed in several studies (16,17,28,29). However, the physiological meaning of these changes remained unclear since conventional approaches to study the role of protein S-acylation rely on complete elimination of this modification through site-directed mutagenesis or pharmacological treatment.…”