Back to the future: new techniques show that forgotten phosphorylation sites are present in contractile proteins of the heart whilst intensively studied sites appear to be absent
Year: 2009
Type: editorial
Abstract: It is well established that several key proteins of the contractile apparatus are phosphoproteins.This includes myosin binding protein C (MyBP-C), troponin T and troponin I.It is also generally accepted that phosphorylation of these proteins alters their functional properties and that this modulation of function through the action of kinases and phosphatases plays a role in tuning the contractile apparatus to physiological demands.The prime example of this is phosphorylation of troponin I and MyBP-C by PKA as part of inotropic and lusitropic responses to b-adrenergic stimulation.What is considerably less certain is the 'where' and 'when' of these phosphorylations.The sites of contractile protein phosphorylation by kinases such as PKA and PKC have been determined in vitro and the consequences of changes in phosphorylation at these sites have been investigated by site directed mutagenesis and transgenic mouse models.What has not been determined is whether these predominantly in vitro measurements in purified proteins and in rodent models have any relevance to the human heart in vivo.Recently several papers have addressed this question with new techniques and the results have been surprising and somewhat disconcerting.Phosphorylation in human and rat troponin I and troponin T has recently been studied using electrospray ionisation and Fourier transform mass spectrometry (Zabrouskov et al. 2008;Sancho Solis et al.
Authors: Steven B. Marston, Jeffrey W. Walker
Institutions: Imperial College London, University of Arizona
Language: English
Subfield: Cardiology and Cardiovascular Medicine
Field: Medicine
Domain: Health Sciences
Open Access status: hybrid
Estimated APC paid: $3,890
OpenAlex ID: W2019345701