RNA Biology
- Using your own words write a summary about a paper you read related with RNA biology and give the reference.
CD8 T cells are cells that work for the immune system that protects the host organism from cancerous cells and viral infections. It causes the death of invading pathogen or tumors by apoptosis. In a condition called contraction, very few cells survive and turn into long-lived memory cells that provide antigen-specific protection.
This article examines the post-transcriptional regulation of gene expression by non-coding RNAs (NcRNA) during development and differentiation of CD8 T cells. NcRNAs include small non-coding RNAs (microRNAs) and long non-coding RNAs (lncRNAs). Expression of genes encoding miRNAs can be controlled by their own promoters or by promoters of other genes. As mature miRNAs are produced, in the final stage of miRNA biogenesis, a strand of miRNA is loaded into the RNA-Induced Silencing Complex (RISC). A fully mature double-stranded miRNA is formed by processing the miRNA intermediate leader by the endonuclease DICER. Contains RISC Agonaute-2 protein. Experiments were conducted on mice to learn the contribution of RNA development to T cell immunity. It was observed that the number of CD4 and CD8 T cells in mice decreased and they had a smaller thymus. With subsequent studies, it was observed that miRNAs were expressed in different ways in different CD8 T cells. The place where traditional pure CD8 T cells mature is the thymus. It has been suggested that miRNAs can be involved and influence direct lineage and thymic selection. miRNA mediated regulation is an important factor in the differentiation of multiple CD8 T cells. Transition through the effector stage of CD8 T cell differentiation and survival during contraction is essential for the proper development of a functional memory pool. miRNAs may have the ability to prevent depletion. It appears to have a potential role in the regulation of depleted T cells. The genomic organization of lncRNAs is more complex than miRNAs. lncRNAs often overlap with protein-coding loci and enable these genes to regulate their expression. LncRNAs can function in the cytoplasm or nucleus and bind DNA, RNA, and proteins. It directly associates with DNA to form R loops that regulate transcription. It has been suggested that there may be as many lncRNA genes as protein-encoding genes in the mammalian genome. LncRNAs with positive regulatory functions were also observed in CD8 T cells. Some lncRNAs cause CD8 T cells to be depleted.
The ongoing study of ncRNAs in CD8 T cells is important not only for our understanding of CD8 T cell and RNA biology, but also for finding treatments for many diseases.
2. Discuss the relationship between RNA structure and function.
RNA's structure is more unstable than DNA. The reasons for this are; In RNA, the pentose ring has 2’ hydroxyl groups and there is a DNA thymine base while the rna has a uracil base. Uracil is more unstable than some thymine base. These make the RNA more unstable. This situation causes the RNA to fold in different ways and therefore the RNA has many different functions. This unstable nature keeps him interacting with different things. Because of these interactions, RNA has a lot of functions inside the cell. RNA has a role not only in the cell but also in some body fluids. I believe we will reach diagnoses and treatments faster in the future through RNA. Especially in viruses and their treatments.
3. Which title interests you most about the subjects we talked about during the semestre and why? Give information about that subject.
The subject of rna editing attracted my attention the most. Because now we will come to the point of changing the base sequence in treatments. In this way, we will can diagnose diseases much earlier and offer definitive treatments. we will can even change not only disease but also some of our physical characteristics.
RNA modifications refer to changes in the chemical structure of RNA molecules that occur after DNA transcription and synthesis by the RNA polymerase enzyme. It is present in all living organisms and is one of the evolutionarily most conserved properties of RNAs. RNA editing can involve the addition, deletion, and base substitution of nucleotides within the RNA molecule. RNA editing can affect the activity, localization, and stability of RNAs and has been associated with human diseases. RNA regulation takes place in the cell nucleus and cytosol, as well as in mitochondria and plastids. The variety of RNA editing phenomena includes nucleobase modifications such as cytidine (C) to uridine (U) and adenosine (A) to inosine (I) deaminations as well as non-template nucleotide additions and deletion.
4. List the RNA types and by using only one sentence explain them.
· Messenger RNA (mRNA): Messenger RNA (mRNA) carries the genetic code from DNA in a form that can be recognized to make proteins.
· Ribosomal RNA (rRNA): In the cytoplasm, rRNAs and protein components combine to form a nucleoprotein complex called the ribosome which binds mRNA and synthesizes proteins.
· Transfer RNA (tRNA): tRNAs are an essential component of translation, where their main function is the transfer of amino acids during protein synthesis.
· Small nuclear RNA (snRNA): snRNA is involved in the processing of pre-messenger RNA (pre-mRNA) into mature mRNA.
· Small nucleolar RNAs (snoRNA): Small nucleolar RNAs are components of small nucleolar ribonucleoproteins (snoRNPs), which are complexes that are responsible for sequence-specific nucleotide modification.
· Piwi-interacting RNAs (piRNA): Piwi-interacting RNAs bind the PIWI subfamily proteins that are involved in maintaining genome stability in germline cells.
· MicroRNAs (miRNA): These RNA species mediate post-transcriptional gene silencing through RNA interference (RNAi), where an effector complex of miRNA and enzymes can target complementary mRNA by blocking the mRNA from being translated or accelerating its degradation.
· Long noncoding RNAs (lncRNA): Long noncoding RNAs are a heterogeneous group of non-coding transcripts larger than 200 nt in size and make up the largest portion of the mammalian non-coding transcriptome.
