Projects per year
Abstract
The "Fight or Flight" response is elicited by extrinsic stress and is necessary in many species for survival. The response involves activation of the β-adrenergic signalling pathway. Surprisingly the mechanisms have remained unresolved. Calcium influx through the cardiac L-type Ca2+ channel (Cav1.2) is absolutely required. Here we identify the functionally relevant site for PKA phosphorylation on the human cardiac L-type Ca2+ channel pore forming α1 subunit using a novel approach. We used a cell free system where we could assess direct effects of PKA on human purified channel protein function reconstituted in proteoliposomes. In addition to assessing open probability of channel protein we used semi-quantitative fluorescent phosphoprotein detection and MS/MS mass spectrometry analysis to demonstrate the PKA specificity of the site. Robust increases in frequency of channel openings were recorded after phosphorylation of the long and short N terminal isoforms and the channel protein with C terminus truncated at aa1504. A protein kinase A anchoring protein (AKAP) was not required. We find the novel PKA phosphorylation site at Ser1458 is in close proximity to the Repeat IV S6 region and induces a conformational change in the channel protein that is necessary and sufficient for increased calcium influx through the channel.
Original language | English |
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Article number | 15118 |
Journal | Scientific Reports |
Volume | 7 |
Issue number | 1 |
DOIs | |
Publication status | Published - 1 Dec 2017 |
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Dive into the research topics of 'Identification of a novel cAMP dependent protein kinase A phosphorylation site on the human cardiac calcium channel'. Together they form a unique fingerprint.Projects
- 6 Finished
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ARC Centre of Excellence in Plant Energy Biology 2014 (CPEB2)
Millar, H. (Investigator 01), Pogson, B. (Investigator 02), Tyerman, S. (Investigator 03), Small, I. (Investigator 04), Whelan, J. (Investigator 05), Borevitz, J. (Investigator 06), Lister, R. (Investigator 07), Atkin, O. (Investigator 08) & Munns, R. (Investigator 09)
ARC Australian Research Council
1/01/14 → 31/05/21
Project: Research
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NHMRC Research Fellowships - Hool
Hool, L. (Investigator 01)
NHMRC National Health and Medical Research Council
1/01/11 → 31/12/16
Project: Research
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Identifying the Sites of Modification on the Human L-type Ca2+ Channel Protein Isoforms During Oxidative Stress with Reference to Development of a Therpeutic Target
Hool, L. (Investigator 01), Ingley, E. (Investigator 02) & Corry, B. (Investigator 03)
NHMRC National Health and Medical Research Council
1/01/11 → 31/12/13
Project: Research