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Genetics and exercise: an introduction
Published in Adam P. Sharples, James P. Morton, Henning Wackerhage, Molecular Exercise Physiology, 2022
Claude Bouchard, Henning Wackerhage
How is a gene “read” to produce a protein? Francis Crick wrote in 1956 something in his notebook which he called the “central dogma”. Today, this unpublished notion is widely known as the central dogma of molecular biology. It describes how the biological information flows in the “DNA → RNA → protein” direction. According to the dogma, DNA is equivalent to the instructions for the book of life. RNA is very similar to DNA, but it is single-stranded, whereas DNA is double-stranded (i.e. the double helix), and the sugar in RNA is a ribose, whereas the sugar in DNA is a deoxyribose. Also known as “messenger” RNA (mRNA), the RNA copies and delivers the DNA “message” to the protein-making machinery of the cell (in the ribosome) to make the protein. The making or synthesis of RNA from DNA is termed transcription (RNA synthesis also described as gene expression) and the process of protein synthesis from RNA is termed translation. Figure 3.7 illustrates Crick’s central dogma. It is important considering recent advances in molecular biology to recognise that the central dogma is incomplete and that there are exceptions to the dogma.
Bacteria
Published in Julius P. Kreier, Infection, Resistance, and Immunity, 2022
To grasp how RNA may be used in taxonomy one must understand the forms in which RNA exists in cells. RNA is found in several configurations and molecular sizes that carry out various functions within cells. Template RNA (tRNA) is an informational molecule, messenger RNA (mRNA) carries information between DNA; the cells′ information storage molecule, and ribsomes, replication molecules that are the site of protein synthesis. rRNA is found in particles of ribonucleoprotein, which may exist free in bacterial cytoplasm. rRNA accounts for about fifty percent to eighty percent of the cells′ total RNA. Ribosomal RNA consists of polymeric subunits that are described on the basis of separation by sedimentation in a solvent (usually water that contains cesium chloride and other salts) in a gravitational field under highly standardized and controlled conditions in an ultracentrifuge; and expressed as Svedberg (S) units. Actually, a time-saving technique that produces cDNA directly from rRNA in the presence of the enzyme reverse transcriptase, followed by analysis of the cDNA is often used in studies of rRNA.
Food Interactions, Sirtuins, Genes, Homeostasis, and General Discussion
Published in Chuong Pham-Huy, Bruno Pham Huy, Food and Lifestyle in Health and Disease, 2022
Chuong Pham-Huy, Bruno Pham Huy
A gene, the basic physical and functional unit of heredity, is made up of deoxyribonucleic acid (DNA). (103–107). A gene is a sequence of nucleotides in a particular nucleic acid (104). The nucleotide is the structural unit of a nucleic acid. It is comprised of phosphoric acid, sugar (5-carbon), and a nitrogenous base. The chains of nucleotides in a nucleic acid are linked by 3′, 5′ phosphodiester linkages (104). Genes control identifiable traits of an organism. Genes are segments of DNA that contain the code for a specific protein that functions in one or more types of cells in the body (106). The information stored in DNA is arranged in hereditary units, now known as genes, that control identifiable traits of an organism. In the process of transcription, the information stored in DNA is copied into ribonucleic acid (RNA), which has three distinct roles in protein synthesis (107). Some genes contain all the information necessary to synthesize a protein (enzyme). However, many genes do not code for proteins (105). In humans, genes vary in size from a few hundred DNA bases to more than 2 million DNA bases (105). Humans have about 20,000 to 25,000 genes (105–106).
Endoplasmic reticulum stress-related signature predicts prognosis and immune infiltration analysis in acute myeloid leukemia
Published in Hematology, 2023
Lu Dong, Haili Wang, Zefeng Miao, Yanhui Yu, Dongzheng Gai, Guoxiang Zhang, Li Ge, Xuliang Shen
The endoplasmic reticulum (ER) is present in various eukaryotic cells and comprises the biofilm system. It is the basis of intracellular protein synthesis and an important site for post-translational modification, folding, and transport of proteins [5, 6]. Tumor cells are often in a microenvironment of ischemia, hypoxia, nutrient deficiency, and low pH during the growth process, which leads to the accumulation of a large number of unfolded or misfolded proteins, causing ER stress. Recent studies have confirmed that ER stress occurs in various tumor cells, leading to various pathological states. ER stress activates three major signaling pathways: the unfolded protein response (UPR), ER overload response (EOR), and sterol regulatory cascades. UPR activation also occurs during hematopoiesis, and increasing evidence supports the cytoprotective role of ER stress in the emergence and proliferation of leukemic cells. Previous studies have shown that ER stress plays an important role in AML pathogenesis [7]. The increased basal UPR is induced, at least in part, by adverse growth conditions in the bone marrow, such as hypoxia [8]. However, the exact role of ER-stress in AML development and progression remains unclear. Therefore, a comprehensive understanding of ER stress can contribute to a better diagnosis and help develop effective treatments for AML.
Pharmacotherapeutic options for cancer cachexia: emerging drugs and recent approvals
Published in Expert Opinion on Pharmacotherapy, 2023
Lorena Garcia-Castillo, Giacomo Rubini, Paola Costelli
The correct balance between protein anabolism and catabolism (proteostasis) is fundamental to maintain skeletal muscle structure and function. In cancer, cachexia proteostasis is altered, markedly favoring catabolic processes, thus contributing to body and muscle wasting [8]. This latter, in particular, can result from increased protein breakdown and/or decreased protein synthesis. Both processes are regulated by several signaling pathways, among which one involving protein kinase B (AKT) activity. In physiological states, active AKT phosphorylates FoxO transcription factors impose their localization in the cytoplasm, thus avoiding the transcription of genes encoding the muscle-specific ubiquitin ligases MuRF1 and Atrogin-1. The overall result is the inhibition of UPS-mediated protein degradation. AKT also promotes protein anabolism by activating the mammalian target of rapamycin complex 1 (mTORC1). In cancer cachexia, the activity of AKT can be inhibited by pro-inflammatory cytokines and angiotensin II, or by reduced levels of insulin-like growth factor 1 (IGF-1), overall leading to altered proteostasis in the skeletal muscle, favoring protein degradation [1].
Exploitation of the antifungal and antibiofilm activities of plumbagin against Cryptococcus neoformans
Published in Biofouling, 2022
Weidong Qian, Wenjing Wang, Jianing Zhang, Yuting Fu, Qiming Liu, Xinchen Li, Ting Wang, Qian Zhang
As shown in Figure 7, 19 DEGs involved in ribosome biogenesis were observed in plumbagin-treated C. neoformans H99 cells in the biofilm and planktonic state. Ribosomes are composed of structural components encoded by ribosomal protein (RP) genes and are the sophisticated molecular machines for protein synthesis as directed by the genetic information encoded by mRNAs. In this study, 12 and seven DEGs in the plumbagin-treated C. neoformans H99 cells were downregulated in the biofilm and planktonic states, respectively. Moreover, the downregulated expression levels of RPL27 (ribosomal protein L27), RPL17, RPL22, RPL2, RPL9B, RPL30 and UBI1 genes in the C. neoformans H99 biofilm state were similar to those in the corresponding planktonic state. In contrast, the expression of RPL39, NOP1, MRPS18 and NOG2 were downregulated in the biofilm state, but were unaltered in the planktonic state.