Regulations Involved in Protein Synthesis

Cells’ ability to replace proteins lost to degradation or export is maintained through a process known as protein biosynthesis, which occurs within cells. Structured proteins, hormones, enzymes, and many more roles are all performed by proteins in the body. Prokaryotes and eukaryotes both go through the same process of protein synthesis, but there are some key differences.

Transcription and translation are the two main stages of protein synthesis. Genes in the human genome contain the instructions for making certain proteins, which are encoded by segments of DNA called messenger RNA (mRNA). In the nucleus of the cell, enzymes known as RNA polymerases carry out this conversion.

What is the regulation of protein synthesis?

One of the most complicated things that a cell does is make proteins. A key part of a living system is how it works during different stages of growth, division, differentiation, development, ageing, and death. Transcribing one mRNA molecule from a gene into a protein requires almost 200 small and large parts to work well and correctly. This process uses a lot of energy from the cell. The main parts of the protein-making machine are ribosomes, initiation factors, elongation factors, amino acids, tRNAs, and aminoacyl-tRNA synthetases. There are three steps to making a protein: initiation, elongation, and termination. After that, posttranslational modifications happen. Rate-limiting factors that control total protein synthesis can be any part of the machinery that makes proteins. Protein synthesis is mostly controlled by how much mRNA is around and how much and how well ribosomes, initiation factors, and elongation factors work. Post-translational changes, like phosphorylation, are made to different parts of proteins after they are made. These changes affect how active and stable the proteins are.

Mechanism and regulation of protein synthesis

Mitochondria are parts of cells that use a process called oxidative phosphorylation to make chemical energy. They come from a bacterial ancestor and have their own genome, which is expressed by special transcription and translation machines in the mitochondria. These machines are different from those that operate in the nucleus. In particular, the machinery for making proteins in the mitochondria is very different in structure and function from the machinery for making proteins in the cytosol of eukaryotic cells. Even though mitochondria have their own DNA, they are not completely separate from the rest of the cell. On the other hand, the health of the cell is closely tied to how well its mitochondria work. Mitochondria depend on the import of proteins that are coded in the nucleus for gene expression and function. To control their proteome, mitochondria have a lot of cross-talk between their different compartments. This connection makes it possible for mitochondria to adjust to changes in the cell’s environment and also helps cells respond to stress and mitochondrial dysfunction. With a focus on mammals and yeast, we look at some of the most important things that have been learned about the biogenesis, architecture, and workings of the mitochondrial translation apparatus in the past few years, thanks to the discovery of many structures close to the atomic level and a lot of biochemical work. We also talk about how mitochondrial protein expression is controlled, including the maturation and stability of mRNA and tRNA, the roles of auxiliary factors, such as translation regulators, that change the rate of mitochondrial translation, and the importance of cross-compartment communication with nuclear gene expression and cytosolic translation and how it allows mitochondrial translation to fit into the context of the cell.

How is protein synthesis regulated in the cell?

Following transcription and RNA processing is translation, which is the production of proteins based on mRNA blueprints. Proteins play a key role in the majority of cellular processes, carrying out the many functions dictated by the genomic DNA sequence. The final stage of gene expression is thus protein synthesis. For a polypeptide chain to be active, it must first fold into the proper three-dimensional conformation and often go through a number of processing stages. Eukaryotic cells, in particular, rely on these processing processes to sort and transport proteins to the correct locations inside the cell, a relationship that is particularly strong.

Even while transcription is the primary mechanism for controlling gene expression, translation can also play a role, and this regulation is critical in both prokaryotic and eukaryotic cells. Cellular proteins’ ability to do what they do depends on systems inside the cells. Covalent modifications or interaction with other molecules are two ways that proteins, once produced, might be controlled in response to extracellular cues. Differential rates of protein degradation can also influence the concentrations of proteins within cells. All elements of cell behaviour are ultimately regulated by these various controls on the levels and activities of intracellular proteins.

CONCLUSION

Changes and mistakes in protein production, through DNA mutations or protein misfolding, often cause disease. DNA mutations modify the mRNA sequence, which modifies the amino acid sequence. Mutations can shorten polypeptide chains by causing early translation termination. Alternatively, a mutation in the mRNA sequence affects the encoded amino acid. This amino acid variation can affect protein function or folding. Misfolded proteins can cause sickness because they tend to clump together. These aggregates are connected to neurological illnesses including Alzheimer’s and Parkinson’s.

mRNA is transcribed from DNA in the nucleus. In eukaryotes, pre-mRNA undergoes post-transcriptional changes in the nucleus to become mature mRNA. In prokaryotes, post-transcriptional changes aren’t needed, because transcription produces mature mRNA instantly.

Ribosomes create polypeptide chains from mRNA during translation. In eukaryotes, translation happens in the cytoplasm, where ribosomes are free-floating or linked to the endoplasmic reticulum. Transcription and translation occur in the cytoplasm of nucleus-less prokaryotes.