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The Role of Epigenetics in Skeletal Muscle Adaptations to Exercise and Exercise Training
Published in Peter M. Tiidus, Rebecca E. K. MacPherson, Paul J. LeBlanc, Andrea R. Josse, The Routledge Handbook on Biochemistry of Exercise, 2020
Emerging evidence suggests that histone modifications could also be an important epigenetic mechanism contributing to exercise-induced transcriptional responses in skeletal muscle. Global histone 3 acetylation at lysine 36 is increased immediately following 60 min of cycling in human skeletal muscle and is associated with the nuclear export of the class IIa histone deacetylases (HDACs) (41). This sub-family of HDACs does not possess activity against acetylated lysine, but acts as scaffolds to recruit transcriptional co-repressors and other HDAC isoforms to specific transcription factors (18), such as MEF2 (45). The phosphorylation-dependent nuclear export of the class IIa HDACs disrupts this transcriptional co-repressor complex, resulting in transcription factor–specific gene expression responses (45). The importance of disrupting this co-repressor complex for the transcriptional response to exercise has been highlighted in a recent study (19). Skeletal muscle expression of HDAC4 and HDAC5 mutants that have impaired recruitment of the co-repressor complex results in an exercise-like transcriptional response and enhanced capacity for lipid oxidation (19). Phosphorylation of the class IIa HDACs appears to be regulated by a number of kinases, including the AMP-activated protein kinase (AMPK) (44), the calcium/calmodulin-dependent protein kinase II (CaMKII), and protein kinase D (PKD) (12), in a redundant fashion (43). These studies delineate important signalling pathways by which exercise can induce specific transcriptional responses through epigenetic mechanisms.
Cognition Enhancers
Published in Sahab Uddin, Rashid Mamunur, Advances in Neuropharmacology, 2020
Ramneek Kaur, Rashi Rajput, Sachin Kumar, Harleen Kaur, R. Rachana, Manisha Singh
Growth associated protein-43 (GAP-43) is another PKC substrate which plays an integral role in cognitive functioning and is linked with the neuronal growth. GAP-43 interacts with actin (just like MARCKS). The phosphorylation of GAP-43 is done by PKC and thereafter it stabilizes the filaments (He et al., 1997). The activation of PKC upsurges autophosphorylated calcium/calmodulin-dependent protein kinase II (CaMKII) level and promotes the association with N-methyl-D-aspartate (NMDA) receptors, probably by phosphorylation of CaMK protein (like neuromodulin) (Yan et al., 2011). The interaction between PKC, calcium/calmodulin-dependent protein kinase II, and cytoskeletal proteins (like actin filaments) changes the dendritic spines geometry and thus, alters the connectivity and function of neuronal network which is responsible for cognition.
Angelman Syndrome
Published in Merlin G. Butler, F. John Meaney, Genetics of Developmental Disabilities, 2019
The UBE3A deficient mouse model provides some insight into regional brain dysfunction with recent work focused on the well-studied phenomenon of long-term potentiation (LTP). Learning in the context of LTP is abnormal in the AS mouse (43,46). In recent LTP studies involving mouse hippocampus, abnormal ratios of phospho-calcium/calmodulin-dependent protein kinase II (CaMKII) have been found. Other downstream effectors of the LPT process such as protein kinase C (PKC) and cAMP-dependent protein kinase A (PKA) appeared to function normally. It appears however that CaMKII is not an actual target for ubiquitylation by UBE3A. Presumably, there is some indirect connection to this protein’s phosphorylation status (43).
Effect of feeding regimen on circadian activity rhythms of food anticipatory by ghrelin hormone in a pig model
Published in Nutritional Neuroscience, 2023
He Zhang, Xiaoxi Yan, Ailian Lin, Pengke Xia, Menglan Jia, Yong Su
Stock solutions were prepared and stored at 4°C until used. The rat acylated ghrelin (Bachem, Switzerland) was prepared in distilled water at a concentration of 10 nM, 100 nM, or 1 μM. The ghrelin antagonist [D-Lys3]-GHRP-6 (Abcam, England) was prepared in distilled water at 10 μM, 100 μM concentrations. Stock solutions of the PKA inhibitor H89 (Selleck, America) and the PLC inhibitor U73122 (Selleck, America) were prepared in dimethyl sulfoxide (DMSO) at 10 μM, 100 μM concentrations, respectively. The calcium/calmodulin-dependent protein kinase II (CaMKII) inhibitor KN93 (Selleck, America), the PKC inhibitor chelerythrine chloride (CHEL; Selleck, America) and the blocker of the endoplasmic reticulum (ER) Ca2+ pump thapsigargin (Abcam, England) were prepared in DMSO at 1 μM and 10 μM concentrations, respectively.
An overview on the recently discovered iota-carbonic anhydrases
Published in Journal of Enzyme Inhibition and Medicinal Chemistry, 2021
Alessio Nocentini, Claudiu T. Supuran, Clemente Capasso
LCIP63 and the homologs identified as bacterial ι-CAs (like BteCAι) show a primary sequence that completely differs from any previously identified CA-class.59,60 For example, LCIP63, at its N-terminal part, displays the presence of an endoplasmic reticulum signal peptide (of 22 amino acid residues) and a chloroplast signal peptide (of 34 amino acid residues)59. It is a multidomain protein with four, three, or two repeated domains, each of them homologous to the calcium/calmodulin-dependent protein kinase II Association Domain (CaMKII-AD)59. The CaMKII-AD belongs to the NTF2-like protein superfamily, which is a group of proteins, sharing a common fold identified for the first time in the structure of the rat NTF2 (Nuclear Transport Factor 2)63. Generally, the polypeptide chain of the bacterial ι-CAs present a pre-sequence of 19 or more amino acid residues at the N-terminal part and contains one or two repeated domains. The amino acid sequence is homologous to a group of proteins annotated as SgcJ/EcaC oxidoreductase family, with an unknown function. These proteins share a common structure with the NTF2-like superfamily, having a hydrophobic pocket that could constitute a putative substrate binding or catalytic active site.
DL-3-n-butylphthalide (NBP) ameliorates cognitive deficits and CaMKII-mediated long-term potentiation impairment in the hippocampus of diabetic db/db mice
Published in Neurological Research, 2019
Ming Gao, Suxiao Ji, Jie Li, Songyun Zhang
The impairment of cognition in diabetes includes reduced information processing speed and impaired memory, attention, and executive functioning [6,7]. Impaired memory and decreased studying ability are related to long-term potentiation (LTP) in neurons. LTP induction in hippocampal area CA1 occurs during learning and can last for a long period [8], making it likely to be a mechanism involved in memory. The process of LTP at hippocampal CA1 synapses is initiated by brief periods of high-frequency presynaptic stimulation. Then, glutamate, the neurotransmitter that is released at these synapses, activates postsynaptic NMDA-type glutamate receptors (NMDARs) and AMPA-type glutamate receptors (AMPARs) [9]. The opening of NMDARs during the induction of LTP leads to calcium entry, which activates calcium/calmodulin-dependent protein kinase II (CaMKII). CaMKII subsequently translocates to the postsynaptic membrane and produces potentiation by phosphorylating subunits of AMPARs and increasing the number of AMPARs at the postsynaptic membrane [10]. NMDAR subtype 2B (NR2B) and AMPAR subtype 1 (GluR1) are pivotal subunits of NMDAR and AMPAR, respectively, in reinforcing LTP [10]. Therefore, we imply that cognitive deficits in T2DM may be caused by deterioration of CaMKII-mediated LTP in the hippocampal CA1 area.