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Genetics of muscle mass and strength
Published in Adam P. Sharples, James P. Morton, Henning Wackerhage, Molecular Exercise Physiology, 2022
Stephen M. Roth, Henning Wackerhage
The actinins, abbreviated ACTNs, are actin-binding proteins located in the Z discs of sarcomeres within skeletal muscle. There are two ACTN isoforms of which ACTN2 is expressed in all muscle fibres, whereas ACTN3 is only expressed in fast type II muscle fibres. Initially, an ACTN3 deficiency was found in patients with muscular dystrophies but then a team led by Kathryn North demonstrated that the absence of ACTN3 is common in individuals with no muscle disease and caused by a so-called ACTN3 R577X polymorphism (29). Using PCR and DNA sequencing, they identified a common C→T single nucleotide polymorphism (SNP) in exon 16 of the ACTN3 gene. This one nucleotide difference in the DNA sequence greatly changes the ACTN3 protein because as a consequence, amino acid 577, which is normally an arginine (abbreviated as R), is changed to a stop codon, abbreviated as X. Hence, the polymorphism is abbreviated as ACTN3 R577X.
Nutrigenomics for Sport and Exercise Performance
Published in Peter M. Tiidus, Rebecca E. K. MacPherson, Paul J. LeBlanc, Andrea R. Josse, The Routledge Handbook on Biochemistry of Exercise, 2020
Nanci S. Guest, Marc Sicova, Ahmed El-Sohemy
The ACTN3 (rs1815739) gene encodes the alpha-actin 3 protein, which plays a key role in the contraction of fast-twitch or power-type muscle fibres during short bursts of intense activities, such as sprinting or lifting heavy objects (154). Genetic variation in ACTN3 affects the expression of the resulting protein in fast-twitch fibres, and individuals who carry at least one copy of the T variant produce a lower-functioning ACTN3 protein that has been linked to increased risk of muscle damage (52). For example, a recent study showed that experienced endurance athletes with the T variant had higher levels of markers of muscle damage after a competitive marathon (38) compared to individuals with the CC variant. A similar trend was observed in a study where healthy young men performed knee extension exercises, working the quadriceps, in a laboratory setting (39).
Hereditary Multiple Osteochondromas
Published in Dongyou Liu, Handbook of Tumor Syndromes, 2020
Germline loss-of-function mutations (e.g., nonsense, frameshift, splice site, missense variants) in the EXT1 and EXT2 genes leading to premature terminations of the EXT proteins cause HS deficiency and subsequent cytoskeletal abnormalities (e.g., actin accumulation, excessive bundling by alpha-actinin, and abnormal presence of muscle-specific alpha-actin) [1].
Hematopoietic stem cell transplantation in systemic autoinflammatory diseases - the first one hundred transplanted patients
Published in Expert Review of Clinical Immunology, 2022
Sara Signa, Gianluca Dell’Orso, Marco Gattorno, Maura Faraci
Null mutations in Actin Related Protein 2/3 Complex Subunit 1B (ARPC1B) may result in a complex phenotype including combined immunodeficiency, platelet abnormalities, and inflammatory manifestations such as vasculitis and eczema [37–41]. The main immunological features consist in T-cell migration defect, lymphoproliferation, and impaired formation of the immune synapse. So far, 7 patients who underwent HSCT have been reported [37–40,42]; two of them received TCRα-β/CD19 depleted stem cell transplantation from haploidentical donor [39,40], whereas the other cases received a RD. Six patients are alive, showing no signs of primary disease, although the mean follow up is of 1 year only. One patient has a longer follow up (6 years) and shows a mixed chimerism but a persistent control of the underlying disease. A seventh patient died due to severe sinusoidal obstruction syndrome (SOS) after HSCT from a RD.
Enhancement in the ATP level and antioxidant capacity of Caenorhabditis elegans under continuous exposure to extremely low-frequency electromagnetic field for multiple generations
Published in International Journal of Radiation Biology, 2020
Yahong Wang, Yongyan Sun, Ziyan Zhang, Zhihui Li, Hongying Zhang, Yanyan Liao, Chao Tang, Peng Cai
Adult worms in the C and E groups were collected at 60 h in the F1 and F15 generations, with approximately 20,000, using real-time fluorescent quantitative PCR to detect changes in the ATP synthase (r53.4, hpo-18, atp-5, unc-32, atp-3) and SOD synthase (sod-1, sod-2, sod-3) mRNA levels. The methods were as follows: RNA was extracted using the Trizol method (Invitrogen, CA, USA), a reverse transcription kit (cDNA Synthesis Kit, Ta Ka Ra) was used to reverse transcribe the RNA into cDNA, and finally, the mRNA expression of the gene was detected using a fluorescent quantitative PCR kit (TB Green TM Premix Ex Taq TM II kit). The relative quantification of targeted genes was detected in comparison with the reference gene actin-1. The relative expression of the gene was determined using the 2−△△t method. The experiment was repeated three times, and the primer sequences involved in the experiment are shown in Table 1.
Novel therapeutic targets for cancer metastasis
Published in Expert Review of Anticancer Therapy, 2020
Konstantin Stoletov, Perrin H. Beatty, John D. Lewis
Finding genes previously validated by other researchers as drivers of cancer cell invasion, such as ACTB and ACTC1, was a good indication that this approach could also identify cell migration related targets. ACTB (β-actin) is a widely distributed cytoskeleton protein involved in eukaryotic cell motility. In tumor cells ACTB expression is either de-regulated or up-regulated leading to abnormal levels and polymerization of ACTB protein, invadopodia formation and metastasis of tumor cells [91]. Researchers studying aggressive brain tumor glioblastoma (GBM) recurrence reported that patients with ACTC1-positive high-grade gliomas had an 87.5% recurrence rate whereas no recurrence was found in the ACTC1-negative glioma patients. ACTC1 may be an effective prognostic and invasive biomarker for GBM [72]. Although not found in the HEp3 shRNA library screen that identified ACTB and ACTC1, another cytoskeleton-associated protein called Karyopherin β1 (KPNB1) was identified in a gene knockdown tumor inhibition screen as critical for tumorigenesis [81]. Among other functions, KPNB1 is a microtubule-kinetochore attachment and nuclear import protein. Many cancers including GBM, high-risk prostate cancer, myeloma, hepatocellular carcinoma, and diffuse large B-cell lymphoma upregulate expression of KPNB1. Knockdown of KPNB1 in cervical cancer cells resulted in prolonged mitotic arrest and apoptosis of the cancer cells, making this gene another potential anti-metastatic target [82].