Dhhc5 Regulates Beta-Adrenergic Signaling In The Heart Through Palmitoylation of G Alpha Proteins

<p>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. The work in this dissertation investigated whether β-adrenergic stimulation led to stimulus-dependent palmitoylation of downstream signaling proteins in immortalized and primary cell models. I found that β-adrenergic stimulation led to rapidly increased Gαs and Gαi palmitoylation only in primary cardiomyocytes. The kinetics of palmitoylation was temporally consistent with the downstream production of cAMP and contractile responses. I 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 Gαs, Gαi, and functional responses downstream of β-adrenergic stimulation. A palmitoylation assay with purified components revealed that Gαs and Gαi 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 in the plasma membrane. My results reveal that DHHC5 is a central regulator of signaling downstream of β-adrenergic receptors in cardiomyocytes.</p>

Name thesis:degree_name

Doctor of Philosophy (PhD)

Level thesis:degree_level

Dissertation (PhD)

Year dc:date.available

2019

Authors dc:creator

• Chen, Jie
• <p>0000-0002-6222-0055</p>

Contributors dc:contributor

• Darren Boehning
• Vasanthi Jayaraman
• Ilya Levental

• Palmitoylation
• DHHC proteins
• Beta-adrenergic signaling
• Medicine and Health Sciences

Repository record dc:identifier

https://digitalcommons.library.tmc.edu/utgsbs_dissertations/960

OAI identifier oai:identifier

oai:digitalcommons.library.tmc.edu:utgsbs_dissertations-2007