Resistance Exercise Training and The Regulation of Muscle Protein Synthesis
Peter M. Tiidus, Rebecca E. K. MacPherson, Paul J. LeBlanc, Andrea R. Josse in The Routledge Handbook on Biochemistry of Exercise, 2020
The coordination of MPS involves the translation of a strand of messenger ribonucleic acid (mRNA) into a fully functioning protein by ribosomes within a muscle cell (41). This process begins in the nucleus, where a strand of mRNA corresponding to the gene to be expressed is produced from deoxyribonucleic acid (DNA) by RNA polymerases. This strand is then exported from the nucleus into the cytosol where various translation initiation factors bind and recruit ribosomal subunits (32). Once the full ribosome has been assembled around a strand of mRNA, the process of translation begins, whereby transfer RNA (tRNA) structures, bound to an AA, are recruited to the ribosome. Here, a peptide bond is formed between the carboxyl group of one AA and the amino group of the next (6, 41). This process is continued as the ribosome moves along the length of the mRNA strand until it reaches a stop codon (29). At this point, the newly formed peptide chain is released from the ribosome and undergoes various folding steps until it reaches its final, functional form (24). A schematic depicting the basic molecular mechanisms governing MPS can be seen in Figure 10.1.
Diamond–Blackfan Anemia
Dongyou Liu in Handbook of Tumor Syndromes, 2020
Ribosome is a cellular structure involved in the translation of messenger RNA (mRNA) to an amino acid sequence (protein). In eukaryotes, ribosome (measuring 80S in size) is separated into the small (40S) and the large (60S) subunit, each of which consists of ribosomal RNA (rRNA) and RP. The large 60S subunit comprises a 5S rRNA, a 28S rRNA, a 5.8S subunit, and ∼46 RP (or RPL, i.e., RP associated with large ribosomal subunit); whereas the small 40S subunit contains 18S rRNA and ∼33 RP (or RPS, i.e., RP associated with small ribosomal subunit). During ribosome biogenesis, RP are synthesized by RP genes in pre-existing ribosomes in the cytoplasm and transferred into the nucleus to assemble with rRNA for new ribosomes. In addition, some RP take part in signaling pathways within the cell that regulate cell division and control apoptosis [9–13].
Structural Organization of the Liver
Robert G. Meeks, Steadman D. Harrison, Richard J. Bull in Hepatotoxicology, 2020
The endoplasmic reticulum (ER) consists of membranes arranged as parallel stacks of flattened cisternae and tubules. Two morphologically distinct regions of the ER can be distinguished (Figure 16): the rough ER (RER), which is studded with ribosomes on the cytoplasmic side of the membrane, and the smooth ER (SER), which is continuous with the membrane of the RER but lacks any attached ribosomes. These two regions also differ considerably in shape; whereas RER is organized in stacks of flattened cisternae, SER consists of a meshwork of tubules. The RER and SER occupy approximately 15% of the total cell volume, or 756 μm3 per rat hepatocyte. The surface area of the ER is estimated to be approximately 63,000 μm2 per hepatocyte or between 7.3 and 11 m3/g liver, with 2.8 mg phospholipid and 4.7 mg protein per m2. The ER of a hepatocyte has about 12.7 x 106 attached ribosomes. In addition to those attached to the membrane of the RER (membrane-bound ribosomes), many ribosomes are also present in the cytosol (free ribosomes) (Weibel et al., 1969; for additional data, see Blouin et al., 1977; Rohr et al., 1976).
Blocking SP/NK1R signaling improves spinal cord hemisection by inhibiting the release of pro-inflammatory cytokines in rabbits
Published in The Journal of Spinal Cord Medicine, 2023
Yuehuan Zheng, Nannan Wang, Zhe Chen, Liqiang Shi, Xiangyang Xu
The normal functioning of the central nervous system (CNS) requires the interaction of multiple cell types, including neurons, glial cells, and non-nerve cells.23 Electron microscopy shows that the nissl body is a ribosome similar to the rough endoplasmic reticulum pool in neurons. Each ribosome is a complex composed of rRNA and proteins that use transfer RNA and amino acids to synthesize proteins from mRNA. In other words, the nissl bodies is a major component of the neuronal protein synthesis mechanism.24 It is reported that the nissl bodies is a large basophilic mass and particle in the neuronal cell body or dendrites. When neurons are damaged, the nissl bodies dissolve and even disappear. During damage recovery, the nissl bodies appear again and reach normal levels. Therefore, nissl bodies can be used as markers of the functional state of neurons.24 In this study, we preliminarily found that the number of nissl bodies increased notably in the spinal cord tissue of the rabbits in the OB group on the 7th day, suggesting that the nissl bodies may be involved in the repair process of SCI.
A click chemistry approach to pleuromutilin derivatives, evaluation of anti-MRSA activity and elucidation of binding mode by surface plasmon resonance and molecular docking
Published in Journal of Enzyme Inhibition and Medicinal Chemistry, 2021
Zhe Zhang, Zhao-Sheng Zhang, Xiao Wang, Gao-Lei Xi, Zhen Jin, You-Zhi Tang
According to the affinity measurement, the selected compounds all showed certain affinities for 50S ribosome. The surface of the chip regenerated well, indicating that there was no irreversible binding between the tested compound and 50S ribosome, which was in line with the Langmuir binding model. Among all the compounds to be tested, compounds 50, 51, 53, 63, 64 and tiamulin showed strong interaction intensity level (10−8 M < KD <10−5 M) for 50S ribosome, and compound 62 showed middle affinity (10−5 M < KD < 10−3 M)30. Compounds 51, 53, 62, 63 have higher Kd values, which means faster dissociation rates and would presumably be difficult to utilise in vivo30. The 50S ribosome was integrated with these derivatives in a dose-dependent manner (Figure SI27–33), while the combination with DMSO was not obvious (Figure SI34). The result suggested that these derivatives were effective in interacting with 50S ribosome through reversible binding. In addition, compound 50 showed the strongest interaction intensity with the macromolecule, followed by compound 64.
Diversity of neuropsychiatric manifestations in systemic lupus erythematosus
Published in Immunological Medicine, 2020
Yuichiro Fujieda
Ribosomes are organelles of protein synthesis and are composed of ribosomal protein–RNA complexes. Ribosomal P protein refers to three types of phosphorylated proteins present on the 60S subunit of eukaryotic ribosomes. It is also known as the neuronal surface P antigen (NSPA) due to their expression on the neuronal cell surface in the cerebral cortex, hippocampus and amygdala [23]. P antigen consists of the highly conserved carboxy-terminal residues of three ribosomal phosphoproteins, P0 (38 kDa), P1 (19 kDa) and P2 (17 kDa) [24]. Anti-ribosomal P protein antibodies recognize all these proteins [25], increase cellular calcium influx and induce cell death [26]. Passive transfer experiments in mice have shown that anti-ribosomal P protein antibodies isolated from SLE patients induce olfactory abnormalities [27], depression-like manifestations [28] and memory impairment [29]. In addition, ribosomal P proteins are expressed on the surfaces of peripheral blood monocytes. Binding of anti-ribosomal P protein antibody to monocytes increases the production of proinflammatory cytokines, such as tumour necrosis factor-α and interleukin (IL)-6 from monocytes [30]. Since these cytokines contribute to the BBB breach, the association between anti-ribosomal P antibodies and BBB breach has recently been considered.
Related Knowledge Centers
- DNA
- Genetic Code
- Peptide
- Ribosomal Protein
- Ribosomal Rna
- Amino Acid
- Messenger Rna
- Molecular Machine
- Cell
- Translation
- Messenger Rna
- Ribosomal Rna
- DNA