In this article we will know about the basics of gene regulation. The work of Gregor Mendel in the eighteen sixties, by way of his experiments with the pea plants, laid the foundation for the laws of inheritance, though the significance of his work wasn't recognized until the early twentieth century. Then came other pioneers like Thomas Hunt Morgan in the early nineteen hundreds, Baba Mackintock, who discovered transposons or jumping genes, followed by the very important discovery of the double helix structure of DNA by James Watson and Francis Crick in 1953, followed by Francois Jacob and Jacques Moreau in 1961 and Andre Leuoff in the nineteen sixties, whose work on lysogeny and bacterial viruses contributed to understanding genetic control mechanisms and he was recognized for his work. There have been other pioneers in the field of genetics and it is not possible to enumerate their work in its entirety over here.
But let us know about the impact of their discoveries. Their discoveries have collectively revolutionized our understanding of genetics from basic inheritance patterns to the intricate regulation of gene expression. The work of these scientists laid the groundwork for modern genetic research, including fields like genomics, biotechnology, and medical genetics. So what are genes? Genes are segments of DNA that serve as the fundamental units for heredity.
They are located on chromosomes, which are long DNA molecules containing a large number of genes. A gene consists of a specific sequence of nucleotides in DNA, which includes regions necessary for its expression, like promoters and enhancers, and the coding sequence, which determines the structure of proteins. What are the various functions that are performed by the genes?
· First is coding of proteins. The primary function of most genes is to store the information needed to produce proteins.
· Then there are regulatory genes. Some genes do not code for proteins but are involved in regulating the expression of other genes. They play a crucial role in turning genes on or off, thus determining when and how much of a protein is produced.
Genes are responsible for hereditary traits ranging from physical characteristics like eye color to predisposition to certain diseases. Genes regulate processes such as cell growth, division, and death, which are essential for the development and maintenance of organisms. Some genes are involved in synthesizing various types of RNA, like ribosomal RNA and transfer RNA, which are crucial for protein synthesis.
How exactly do genes work?
They work through transcription and translation. The information in a gene is first transcribed into messenger RNA or mRNA and then translated into a protein.
This process involves complex machinery including RNA polymerases, ribosomes, and various regulatory proteins. Genetic variability: Small variations in the sequence of a gene, also called mutations, can lead to changes in the protein it encodes, which can affect an organism's traits and sometimes lead to disease. The importance in research and medicine of genes is in understanding diseases. Like many diseases include genetic disorders, and some types of cancers are linked to genetic mutations. Its importance in biotechnology. So, genes are basics of genetic engineering and biotechnology, which have applications in medicine, agriculture, and industry.
The significance of gene up regulation, it is essential for responding to environmental changes and internal signals. It plays a critical role in processes like immune response, adaptation to stress, and development. Now coming to the down regulation of gene expression. Down regulation is the process by which a cell decreases the production of a specific gene product. This involves reducing the gene's transcription and translation.
How does it occur?
It occurs by decreasing the transcription of mRNA from the gene, reducing the stability of mRNA, leading to its quicker degradation, and decreasing the efficiency of translation, resulting in less protein production. The triggers of this are negative feedback mechanisms to maintain homeostasis and hormonal signals, nutrient levels, or other cellular signals indicating a reduced need for a specific protein. The examples of down regulation are cells down regulate the product of enzymes involved in glucose metabolism when glucose levels are low. Hormone receptors on cell surfaces are downregulated after prolonged exposure to high levels of the hormone to prevent overstimulation.
What is the significance of downregulation?
It is crucial for preventing overactivity of cellular pathways and maintaining balance in the cell. It is important in processes like cellular signalling, energy conservation, and preventing harmful overexpression of proteins.
The promoter region, the process begins at a specific region of DNA which is known as the promoter. Many eukaryotic promoters contain a TATA box or a sequence rich in adenine and thymine, which is located about 25 to 30 base pairs upstream of the transcription start site. The transcription factors bind to the promoter region. Some transcription factors specifically recognize and bind to the data box. In eukaryotes, RNA polymerase II is recruited to the promoter by these transcription factors.
Once processing is complete, the mature mRNA is transported out of the nucleus and into the cytoplasm through nuclear pore complexes. There, translation occurs. So in the cytoplasm, the mRNA binds to ribosomes, the cellular machinery for protein synthesis. Transfer RNA, which is tRNA, molecules bring amino acids to the ribosomes, where they are added to the growing polypeptide chain in the order specified by the mRNA sequence. The ribosome moves along the mRNA, translating the nucleotide sequence into a sequence of amino acids, thus forming a polypeptide chain.
How exactly are genes regulated?
The first step in gene regulation often involves controlling access to the DNA. Chromatin remodelling can either expose or hide certain regions of DNA determining whether genes are accessible for transcription. Then specific proteins called transcription factors bind to DNA near the gene. Some transcription factors act as activators, enhancing the gene transcription, while others are repressors that inhibit transcription. The binding of transcription factors facilitates or hinders the attachment of RNA polymerase to the DNA, controlling the initiation of transcription. Coming to the post transcriptional regulation. Once an mRNA molecule is transcribed, it undergoes various processing steps, including splicing, capping, and addition of a polyethyl. Alternative splicing can generate different mRNA variants from the same gene.
Proteins and microRNA can bind to the mRNA and either prevent or promote its translation into a protein. Coming to the post translational regulation. After a protein is synthesized, it can be modified in various ways like phosphorylation, glycosylation, that affect its ability, stability, or location in the cell. The stability and function of proteins are also regulated by controlled degradation processes like ubiquitination targeting proteins for destruction in the proteasome. There are feedback mechanisms.
They are typically about 20 to 25 nucleotides long and function in the post transcriptional regulation of gene expression. Here's an overview of how microRNA act as gene regulations. There is biogenesis of microRNA. MicroRNA are transcribed from DNA as long primary transcripts called pre microRNA, which are then processed into precursor microRNA in the nucleus by an enzyme called drossier. These premicro RNAs are exported from the nucleus to the cytoplasm.
The first is messenger RNA degradation. The target messenger RNA is cleaved and degraded. Enumerating the function of microRNAs. So, microRNAs are involved in the regulation of developmental timing and differentiation of cells. They play a crucial role in controlling the cell cycle and apoptosis, which is programmed cell death. MicroRNAs are also important in regulating various metabolic processes. They help cells respond to stress and environmental changes.
They are typically about 20 to 25 nucleotides long and are involved in post transcriptional gene silencing. Here's an overview of how small interfering RNAs function as gene regulators. These RNAs can originate from long double standard RNAs precursors. These double standard RNAs may be from exogenous sources such as viruses or from endogenous sources such as transposons and repetitive elements. The double standard RNA is recognized and cleaved into short double standard fragments by an enzyme called Dicer.
What are the therapeutic challenges and developments in this field?
So, a significant challenge in using RNA therapeutically is the efficient and targeted delivery to the desired cells. Ensuring specificity and minimizing off target effects are crucial for the safe use of small interfering RNA in therapy. Then comes the question of enhancing the stability of RNAs in the bloodstream that is important for their effectiveness as therapeutic agents. RNAs represent a powerful tool for gene silencing and have significantly contributed to our understanding of gene function and regulation. Their potential in therapeutic applications, especially in targeting specific disease related genes, continues to be a major area of research in molecular biology and medicine.
How can Medline Academics and Dr. Kamini Rao Hospitals help you in this journey?
When you want to learn from the best, don’t just join any institution. Join the best IVF training centre in India – Medline Academics. This institution offers multiple courses in hybrid mode including the most demanded programs like Fellowship in Reproductive Medicine in India and Fellowship in Embryology. Being a year long course, the theory is covered online and a three-week practical training is covered offline in their centre in Bangalore. The duration of the practical training for different programs often varies. Besides the Hybrid Mode, Medline Academics also offers complete online courses and offline courses.
The best IVF centre in Bangalore – Dr. Kamini Rao Hospitals, is a unit of Medline Academics. In addition to the regular course structure, the institution gives their students a chance to observe the best cases and in certain cases even handle the cases with expert guidance. Located in the heart of the city, this hospital is always busy with patients who come with hope and the pioneer Padma Shri Prof. Dr. Kamini A Rao along with her expert team of doctors fulfil their wishes. This institution is not just a centre for learning, it is also a centre for healing.
Comments
0 comment