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Role of Epigenetics in Immunity and Immune Response to Vaccination
Published in Mesut Karahan, Synthetic Peptide Vaccine Models, 2021
miR-451 is frequently found in extracellular vesicles and it alters the immune response to whole-virus vaccines against influenza. Its internalization into macrophages downregulates type I interferon (IFN) and interleukin 6 expression in response to whole-virus vaccines (Okamoto et al. 2018). Gannavaram et al. have illustrated additional roles for miRNA in vaccine immunity. miR-21 expression determines the early vaccine immunity induced by LdCen−/− immunization. First, they generated centrin gene-deleted Leishmania donovani parasites (LdCen−/−) as live attenuated vaccines against leishmaniasis. Their findings suggested that exposure to this antigen suppresses miR-2, which in turn facilitates IL-12-mediated activation of adaptive immunity and development of a Th1 immunity (Gannavaram et al. 2019). In another study conducted to investigate the effect of H1N1 vaccination on serum miRNA expression in children, miR-142-3p was found to be downregulated following vaccination. Nevertheless, the results could not be replicated in a validation cohort (Drury, Pollard, and O’Connor 2019).
Role of cAMP, Calcium, and Protein Phosphorylation in Sperm Motility
Published in Claude Gagnon, Controls of Sperm Motility, 2020
It is probable that not all effects of calcium on flagellar movement are meditated by calmodulin. In the process of characterizing calcium-binding proteins in dog sperm by 45Ca2+-overlay,26 although a band corresponding to calmodulin was a major signal, at least ten minor calcium-binding bands between 100 and 14 kDa were detected.81 Calcium has been shown to cause marked dose-dependent changes such as bending of bull sperm flagella in the absence of ATP.62 This is in support of the “biased baseline” component of flagellar movement proposed by Eshel and Brokaw.63 This hypothesis suggests that calcium regulates flagellar-bending symmetry by modifying the extent of static curvature at the base of the flagellum. A major protein present in the basal root and adjacent regions of cilia and flagella that is known to undergo contraction in the presence of calcium is caltractin (sometimes called centrin).64 This protein contracts in the presence of calcium and is present in a phospho-and dephospho-form. It has been suggested that the cycling between the contracted and relaxed form of the caltractin involves an interplay between calcium and regulation of the phosphorylation state of the protein.
Xeroderma Pigmentosum and Other DNA Repair-Deficient Photodermatoses
Published in Henry W. Lim, Herbert Hönigsmann, John L. M. Hawk, Photodermatology, 2007
Mark Berneburg, Kenneth H. Kraemer
GGR is a second form of repair that is carried out throughout the whole genome. GGR is slower than TCR. In this subpathway DDB2 recognizes the damage attracting a heterodimer of the XP-C protein and the human HR23B along with centrin 2. Cells from XP patients with defects in DDB2 (XPE) or XP-C are defective in GGR but not in TCR (8).
Focus on centrin in normal and altered human spermatozoa
Published in Systems Biology in Reproductive Medicine, 2023
Elena Moretti, Daria Noto, Roberta Corsaro, Giulia Collodel
Centrins are proteins involved in many cell pathways and, despite the large number of available studies, there are many unsettled issues. In this review, we have revised and discussed the role of centrins in human reproduction. To clarify the importance of this protein in reproduction, it is essential to address several issues. First, studying the centrin molecular structures could address unsolved questions of the Ca2+ affinity of the different isoforms. Knowledge of the centrin mechanism of action would benefit the comprehension of Ca2+-binding modalities and the conformational changes of these proteins.