CaMKII oxidation is a performance/disease trade-off in vertebrate evolution

Abstract

32 33 34 Reactive oxygen species (ROS) contribute to health and disease. CaMKII is a widely 35 expressed enzyme whose activation by oxidation of regulatory domain methionines (ox-36 CaMKII) contributes to cardiovascular disease, asthma, and cancer. Here we integrate 37 comparative genomic and experimental data to show that CaMKII activation by ROS 38 arose more than half-a-billion years ago on the vertebrate stem lineage where it constituted 39 a bridge between ROS and increased intracellular Ca 2+ release, exercise responsive gene 40 transcription, and improved performance in skeletal muscle. These enhancements to fight-41 or-flight physiology were likely key in facilitating a well-evidenced shift in the behavioural 42 ecology of our immediate chordate ancestors, and, in turn, the evolutionary success of 43 vertebrates. Still, the ox-CaMKII innovation for augmenting performance must be 44 considered a critical evolutionary trade-off, as it rendered us more susceptible to common 45 and often fatal diseases linked to excessive ROS. 46 examples include: a prechordal head with complex organs of special sensation and a fully 93 differentiated forebrain, a cartilaginous internal skeleton, muscular pharyngeal arches supporting 94 advanced respiration, a more powerful heart pumping blood containing haemoglobin-rich red-95 blood cells, and a sympathetic nervous system and elaborate endocrine glands supporting a fight-96 or-flight physiological response. Many of these novel functional complexes were developmental 97products of a newly evolved population of highly migratory and multipotent neural crest cells, 98and, ultimately, the entire suite of derived vertebrate features may well owe its existence to a 99 greatly expanded genetic tool kit made available by one, and possibly, two full rounds of genome 100 duplication 16 . At some level, all of these innovations promote an increasing level of activity that 101 must be enacted through the skeletal (striated) musculature; so, it was with the physiology of 102 skeletal muscle that we tested for potential beneficial effects of ox-CaMKII. 103 104CaMKII activity contributes to skeletal muscle function 17,18 , so we hypothesized that gaining the 105 MM motif allowed ROS to enhance skeletal muscle performance through ox-CaMKII. We set 106 out to test whether MM residues could dynamically respond to ROS in muscle fibres to increase 107CaMKII activity. To measure the dynamic change of CaMKII activity in muscle fibres, we 108 developed a fluorescent reporter that translocates from the nucleus to the cytosol in response to 109 increased activity of CaMKII (kinase translocation reporter, or KTR, Extended Data Fig. 3a and 110 b and Methods) 19 . We validated the reporter in RPE-1 cells by showing that it translocated into 111 the cytosol when the cells were treated by histamine (Extended Data Fig. 3c and d), which 112 transiently increased cytosolic Ca 2+ concentration 20 (data not shown). This translocation was 113 enhanced by co-expressed exogenous CaMKII, and blunted by co-expre...

O-GlcNAcylation, oxidation and CaMKII contribute to atrial fibrillation in type 1 and type 2 diabetes by distinct mechanisms

“…The findings in the S280A mice in T1D were unexpected because of published evidence that OGN of CaMKII at S280 is required for hyperglycemia induced ROS, SR Ca 2+ leak and triggered ventricular arrhythmias (31, 44). In order to determine if increased OGN detected in diabetic mouse myocardium could directly increase CaMKII activity, we used a novel fluorescent kinase reporter, recently validated in RPE-1 cells and mouse skeletal muscle (72, 73), based on work by Regot and colleagues (72). The fluorescent kinase translocation reporter (KTR) dynamically moves from the nucleus to the cytosol in response to kinase activation (Fig 4A) and the ratio of cytosol/nuclear distribution of the CaMKII-KTR fluorescent signal is a reliable measure of intracellular CaMKII activity (73).…”

“…In order to determine if increased OGN detected in diabetic mouse myocardium could directly increase CaMKII activity, we used a novel fluorescent kinase reporter, recently validated in RPE-1 cells and mouse skeletal muscle (72, 73), based on work by Regot and colleagues (72). The fluorescent kinase translocation reporter (KTR) dynamically moves from the nucleus to the cytosol in response to kinase activation (Fig 4A) and the ratio of cytosol/nuclear distribution of the CaMKII-KTR fluorescent signal is a reliable measure of intracellular CaMKII activity (73). Isolated neonatal mouse cardiomyocytes transfected with CaMKII-KTR virus, 24 hours of after isolation, were cultured in low glucose (5.5 mM glucose) or high glucose (30 mM glucose) for 18 hours.…”

“…Construction and validation of the CaMKII kinase activity reporter (CaMKII-KTR) was recently described by our lab in RPE-1 cells and skeletal muscle fibers (73), based on the initial work by and collaboration with Regot et al (72). CaMKII-KTR was transfected (JetPrime Transfection Reagent, PolyPlus, France) into neonatal mouse cardiomyocytes 24 hours post-isolation.…”

“…Image analyses were carried out in ImageJ (US National Institutes of Health, Bethesda, MD, United States). The cytosolic to nuclear KTR signal ratios were calculated using the mean intensities measured from the nuclei and cytosolic ring (area immediately perinuclear) of individual cells (72, 73).…”