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Notes on Genetic and Radiation Control of Senescence
Published in Nate F. Cardarelli, The Thymus in Health and Senescence, 2019
Nucleoprotein components can be conveniently classified as nucleic acids, histones, and nonhistones.23 By the 1950s it was apparent that there were several types of histones.24–28 Today we recognize two major classifications: cell cycle and basal histones. Most are cell cycle dependent, but about 5 to 10% are basal, as evidenced by their synthesis in nondividing cells, whether quiescent or terminally differentiated.29 There are five classes of histones in the higher vertebrates that are mostly synthesized during the S phase of the cell cycle. Histone genes are repeated tens of times in each genome without intervening sequences.
The Importance of Sperm Surface Markers in Reproductive Success: Sperm Hyaluronan Binding
Published in Nicolás Garrido, Rocio Rivera, A Practical Guide to Sperm Analysis, 2017
The formation of mature spermatozoa requires a series of meiotic and mitotic changes in both the nuclear and the cytoplasmic compartments including the histone–transition protein–protamine replacement. First, somatic histones are replaced by testis-specific histone variants, which are then replaced by transition proteins in a process that involves extensive DNA rearrangement and remodeling.48 During the final postmeiotic phases of spermatogenesis, sperm chromatin compaction occurs and almost 85% histones are replaced by protamines (protamine 1 and protamine 2).49 In the end, sperm chromatin becomes a highly organized compact structure consisting of DNA and heterogeneous nucleoproteins.
Measles Virus
Published in Sunit K. Singh, Human Respiratory Viral Infections, 2014
Rory D. de Vries, Rik L. de Swart
The nucleoprotein (N) mRNA is produced first, since it is at the promoter-proximal position of the genome. The main function of the N protein is to encapsidate the genomic RNA. Since one N protein covers 6 nt, the genome lengths of morbilliviruses obey the “rule of six” (i.e., the genome length must be a multiple of six nt).5
Investigational PARP inhibitors for the treatment of biliary tract cancer: spotlight on preclinical and clinical studies
Published in Expert Opinion on Investigational Drugs, 2021
Rutika Mehta, Anthony C Wood, James Yu, Richard Kim
BRCA1/2 mutations are reported in up to 5.0% of all BTCs with BRCA2 mutations more frequently reported in GBCs [5,13,28]. Both BRCA1 and BRCA2 are involved in the HR repair (hereafter referred to as HRR) process, which plays a major role in DSB repair. A DSB is detected by an MRN complex comprised of the meiotic recombination 11 homologue A (MRE11A)-Nijmegen breakage syndrome 1 (NSB1)-RAD50. BRCA1 now aids in the resection of 5ʹ DNA on either side of DSB, thus exposing single-strand DNA (ssDNA). With the help of BRCA2, DNA recombinase RAD51 is localized to the ssDNA. This RAD51 bound to DNA forms a nucleoprotein that initiates the homologous repair process. With the help of ligases and endonucleases, a successful HRR is completed. When HRR fails, such as when homologous DNA is unavailable, DNA is repaired by end joining, which usually results in DNA deletions. If these deletions occur is crucial tumor suppressor genes, then these lead to tumorigenesis [21]. In vitro studies have shown that mouse cell lines lacking Brca1 or Brca2 have enhanced use of NHEJ, and this leads to higher frequency of DNA deletions [29].
In vitro cytotoxicity of polyphenols from Datura innoxia aqueous leaf-extract on human leukemia K562 cells: DNA and nuclear proteins as targets
Published in Drug and Chemical Toxicology, 2020
Elham Chamani, Roshanak Ebrahimi, Khatereh Khorsandi, Azadeh Meshkini, Asghar Zarban, Gholamreza Sharifzadeh
Studies have shown that DNA is a pharmacological target of many of the drugs currently in clinical use or in advanced clinical trials (Hurley and Boyd 1988, Sirajuddin et al. 2013). In the eukaryotes, nuclear DNA interacts with histone proteins and forms a nucleoprotein complex known as chromatin. Chromatin arranges the nuclear genome into a restricted volume. The first level of chromatin organization consists of DNA-folding around histone proteins to shape the fundamental unit of the chromatin, the nucleosome (Hübner et al. 2013). In a nucleosome, 147 bp of DNA are enfolded in an octamer with two copies of four core histone proteins (H2A, H2B, H3, and H4) (Nair and Kumar 2012). As a linker histone, histone H1 surrounds the chromatosome by protecting the internucleosomal linker DNA near the nucleosome entry-exit point (Dixon et al. 2016, Kalashnikova et al. 2016).
Patterns of antibody response during natural hRSV infection: insights for the development of new antibody-based therapies
Published in Expert Opinion on Investigational Drugs, 2018
Natalia Muñoz-Durango, Magdalena S. Pizarro-Ortega, Emma Rey-Jurado, Fabián E. Díaz, Susan M. Bueno, Alexis M. Kalergis
Another protein that has gained interest in the immunotherapeutic field is the nucleoprotein (N). This protein is part of the internal component of the virion [8] and plays a key role in modulating the immune response during hRSV infection [99–101]. In that field, our research group was pioneer at demonstrating that the hRSV N protein has the ability to interfere with the immunological synapse between antigen-presenting cells and T cells via the surface expression of N protein in the antigen-presenting cells [99,100]. These findings suggest that it is necessary to consider other viral proteins involved in the pathogenesis of the hRSV disease, since viral fusion is not the unique mechanism to be targeted during the infection process. Along these lines, we have developed a recombinant BCG that expresses the hRSV N protein (rBCG-N-hRSV) [101–104]. In addition to be safe, rBCG-N-hRSV induced a Th-1-biased immune response in preclinical models that prevented hRSV-associated disease in various animal models [101–103,105]. This vaccine also induced the generation of IgG1 and IgG2a antibodies, with neutralizing capacity, against various of the hRSV antigens. Due to these promising results, currently a phase I clinical trial is ongoing to evaluate the safety and immunogenicity of rBCG-N-hRSV vaccine (NCT03213405). Concomitantly, various hRSV N protein-specific mAbs have been developed to evaluate their potential as new therapies for hRSV infection [106].