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Plant Biotechnology
Published in Firdos Alam Khan, Biotechnology Fundamentals, 2020
The success of transgene expression is generally based on transcription of mRNA and then into translation leading to protein synthesis. Promoter is a sequence of nucleic acids where RNA polymerase (a complex enzyme synthesizing the mRNA transcript) attaches to the DNA template. The nature of the promoter defines (together with other expression-regulating elements) under which conditions and intensity a gene will be transcribed. The promoter of the 35S gene of cauliflower mosaic virus (CaMV) is used very frequently in plant genetic engineering. This promoter confers high-level expression of exogenous genes in most cell types from virtually all species tested. As it is often advantageous to express a transgene only in certain tissues or quantities or at certain times, several other promoters can also be used such as promoters inducing gene expression after wounding or during fruit ripening only. Methods of gene transfer currently employed result in the random integration of foreign DNA throughout the genome of the recipient cells. The site of insertion may have a strong influence on the expression levels of the exogenous gene, resulting in different expression levels of an introduced gene even if the same promoter/gene construct was used. The exact mechanism of this phenomenon is not yet fully understood (Figure 6.8).
Biomolecular Processing and Molecular Electronics
Published in Sergey Edward Lyshevski, Molecular Electronics, Circuits, and Processing Platforms, 2018
In nucleic acids, monomers are four types of nucleotides that differ in their nitrogenous bases. Genes are typically hundreds or thousands nucleotides long, and each gene has a specific sequence of nitrogenous bases. A protein also has monomers arranged in a particular linear order, but its monomers consist of 20 amino acids. Transcription and translation processes (steps) are involved: Transcription is the synthesis of RNA under the direction of DNA. Agene’fs unique sequence ofDNAnucleotides provides a template for assembling a unique sequence of RNA nucleotides. The resulting RNA molecule (called the messenger RNA and denoted as mRNA) is a transcript of the gene’s protein-building instructions. Thus, the function of mRNA is to transcript a genetic code from the DNA to the protein-synthesis machinery of the cell. Translation is the synthesis of a polypeptide that occurs under the direction of mRNA. The cell must translate the base sequence of an mRNA molecule into the amino acid sequence of a polypeptide. The sites of translation are ribosomes, with many enzymes and other agents facilitating the orderly linking of amino acids into polypeptide chains. The sequence chain is: DNA → RNA → protein.
Devising and Synthesis of NEMS and MEMS
Published in Sergey Edward Lyshevski, Nano- and Micro-Electromechanical Systems, 2018
In nucleic acids, the monomers are four types of nucleotides that differ in their nitrogen content. Genes are typically hundreds or thousands of nucleotides long, and each gene has a specific sequence of bases. A protein also has monomers arranged in a particular linear order, but its monomers are 20 amino acids. Correspondingly, nucleic acids and proteins contain information in two distinct forms. The so-called transcription and translation processes (steps) are involved. Transcription is the synthesis of RNA under the direction of DNA. Both nucleic acids use the same “language,” and the information is simply copied (translated) from one molecule to other. A gene’s unique sequence of DNA nucleotides provides a template for assembling a unique sequence of RNA nucleotides. The resulting RNA molecule (called the messenger RNA and denoted as mRNA) is a transcript of the gene’s protein-building instructions. Thus, the function of mRNA is to transcribe a genetic message from DNA to the protein-synthesis machinery of the cell. Translation is the concrete synthesis of a polypeptide that occurs under the direction of mRNA. The “language” is changed. The cell must translate the base sequence of an mRNA molecule into the amino acid sequence of a polypeptide. The sites of translation are ribosomes, i.e., complex particles with many enzymes and other agents that facilitate the orderly linking of amino acids into polypeptide chains. Though there exist differences in how transcription and translation are organized for prokaryotes and eukaryotes, genes program protein synthesis by sending genetic messages in the form of RNA. The sequence chain is DNA → RNA → protein.
Plant responses to per- and polyfluoroalkyl substances (PFAS): a molecular perspective
Published in International Journal of Phytoremediation, 2023
Ayesha Karamat, Rouzbeh Tehrani, Gregory D. Foster, Benoit Van Aken
The development of -omics technologies have revolutionized biological sciences, including plant biology. Although the entire genetic material of an organism is referred to as the genome, the expression of genes generates transcripts (messenger RNAs–mRNAs), which together constitute the transcriptome. Transcripts are then translated into proteins, which together constitute the proteome. Proteins, mostly enzymes, mediate biochemical reactions of the metabolism, resulting in the synthesis of a multitude of small molecules forming the metabolome (Abdullah-Zawawi et al. 2022). Studying the transcriptome, proteome, and metabolome constitutes therefore a powerful approach for understanding the molecular mechanisms of the plant response to stress, including toxic chemicals, such as PFAS.