Research Paper On Nucleosomes

histone – these are a type of protein that help to organize the DNA. There are 8 histones that make up one group. Each have tails that are covered with chemical tags and stick out of the protein grouping. The chemical tags on the tails affect how they interact with DNA.

The EZH2 (enhance of zeste homolog2) is an enzyme that in humans is fixed by EZH2 and its supply the information’s about making of enzyme called a histone me-thyltransferase. The ploycomb group (PcG) is a protein with the catalytic subunit of the PRC2 (polycomb repressive complex) which the transcriptional involved in maintaining the repressive of genes cells and also the EZH2 mainly performs as a silence gene. The EZH2 performs the role by addition of methyl groups on the ly-sine 27 of histone H3, a modification leading chromatin

RNA polymerase can bind to the promoter region of the DNA even when the lac repressor is bound to the operator site.

Molecular Cell Biology, 7th Edition, 2013, Lodish, Berk, Kaiser, Krieger, Bretscher. Ploegh, Amon, and Scott. W.H. Freeman and Company (ISBN-13: 978-1-4292-3413-9)

The association of FMRP with ribosomes is mRNA dependent via large ribonucleoprotein (RNP) particles. RNP particles contain other proteins including FXR1P, FXR2P, YB-1, CYFIP1, CYF1P2, NUFIP1 and nucleolin.

It has been suggested that abnormalities in the activity or expression of HDACs can lead to an imbalance of HDAC relative to histone acetyltransferase activity resulting in diminished expression of regulatory genes, which control the cell cycle and apoptosis developing tumorigenesis (Licciardi, Ververis, Hiong & Karagiannis, 2013). In some cases, HDAC enzymes are abnormally recruited to gene promoters, which constitutively repress gene expression causing cancer. In addition, HDACs alter gene expression due to the posttranslational deacetylation modification of various nonhistone protein substrates, such as DNA-binding proteins, DNA-repair proteins, transcription factors, signal-transduction molecules, and chaperone proteins(Licciardi, Ververis, Hiong & Karagiannis,

Histones are a protein which DNA is wrapped around. The genes that are loose while wrapped around the histones are easy to read which cause them to be expressed or “on”. On the contrary, the genes tightly coiled aren’t read making them silent or “off”. Whether a certain gene is expressed or silent is determined by the environment and your lifestyle.

Eukaryotic cells contain a sphere-shaped nucleus that protects the genetic information (DNA) and separates it from the cytoplasm. The nucleus itself is protected by a double membrane called, the nuclear envelope. The nuclear envelope is made up of nuclear membranes, nuclear lamina, and nuclear pore complexes. The nuclear lamina is the sturdy protein that gives the nucleus its structure and shape. As well as providing structural support, “the nuclear lamina is required for most nuclear activities, such as chromatin organization, DNA replication, cell cycle regulation, nuclear positioning within the cell, assembly/disassembly of the nucleus during cell division, as well as for modulating master regulatory genes and signaling pathways.” (Baek, McKenna, Eriksson; 2013) The ability of the cell to

the DNA. Binding of the regulatory protein activates transcription which results in the production of mRNA product which is then translated to protein product.

Investigation into the regulation of covalent histone modifications at enhancers and promoters has become a popular research interest due to the important role these modifications have on altering gene expression and modulating cell fate specification. Polycomb repressive complex 2 (PRC2) is a transcriptional repressive complex that consists of three components: enhance zeste 2 (EZH2), embryonic ectoderm development (EED) and suppressor of zeste 12 (SUZ12). The catalytic subunit, EZH2, can methylate lysine 27 of histone 3 (H3K27) to promote transcriptional silencing by facilitating chromatin compaction. Alterations of this complex have been

DNA to Proteins The DNA is a complicated thing and on the topic of DNA there are many subtopics. Subtopics like polypeptides. Polypeptides are bonds of amino acids that are basically proteins. These polypeptides are created through a process in which the DNA is transcribed and then translated with mRNA. Each DNA triplets are transcribed and the RNA copies its code, then each codon creates an amino acid and makes a chain of protein, and that is how a polypeptide is created. This entire procedure takes place in the cell and the process is ended with the use of ribosomes. Ribosomes act as the “zipper” that pulls tRNA and mRNA together and these ribosomes are commonly found on the endoplasmic reticulum or free floating in the cytoplasm of the cell.

The polymerase cofactor VP35 is a protein in the nucleocapsid that just as VP24, possesses the ability to inhibit interferon signaling.14 Also it probably regulates the transcription and replication.15

Gene expression can be altered by different genetic and epigenetic mechanisms. These mechanisms can alter chromatin structures and the accessibility of DNA, thereby regulating patterns of gene expression (Wajed, S. A., Laird, P. W., & DeMeester, T. R. 2001). In the nucleus of the cell, chromatin is bound to a DNA-histone-protein complex in the form of chromosomes. Within the cell, chromatin modifications are made such as DNA methylation and histone modification in order to alter gene expressions. DNA Methylation involves the addition of a methyl group to the 5’ end of the cytosine ring within CpG dinucleotides. While most CpG dinucleotides are methylated, unmethylated CpGs are clustered together at promoter regions of many genes (Lim, D. H., & Maher, E. R. 2011). These promoter regions are essential for transcription to occur, however, DNA methylation can prevent transcription factors from binding leading to changes in chromatin structures. Another mechanism that can alter gene expression is histone modifications. Histone modification includes changing the composition of histones or the addition of acetyl, methyl or phosphate groups onto the amino acids of histone tails (Book). While histones are important proteins used to organize and wrap large amounts of DNA, when histones within these nucleosomes are modified, the mobility and positioning of DNA are affected resulting in gene promoters to be activated or repressed. In addition to both of

Deoxyribonucleic (DNA) is the molecule that hold the genetic information of living things. In our body every cell contains about 2 meters of DNA. DNA is copied every time a cell divides. Deoxyribonucleic (DNA) is made up of two polynucleotide strands. Polynucleotide strands twist around each other, forming a shape that looks like a ladder called a double helix. The two polynucleotide strands run antiaparallel to each other with nitrogenous bases this means that the stands run in opposite directions, parallel to one another. The DNA molecule consists of two backbones chains of sugars and phosphate groups. The organic bases held together by hydrogen bonds. Although bases bonded together are termed paired

Each repeat comprised of 33 to 34 amino acids. Different repeats vary mostly at position 12 and 13. Amino acids present at these two positions are called repeat variable di-residues (RVDs). Each RVD has preference for a nucleotide. Repeats are modular and can be assembled in required way to bind with any target DNA sequence (Gaber et al, 2014; Meckler et al, 2013). TALEs are thus a powerful and modular tool, which can be engineered to target any DNA sequence. Riboswitches are non-protein coding regulatory RNA, present in 5´ untranslated (UTR) region of mRNA, that upon binding with small molecules or peptides undergo conformational changes to control gene expression at translational level. Riboswitches are conceptually comprised of two parts (i) ligand specific aptamer domain, and (ii) expression platform, which undergoes structural changes in response to the changes in the aptamer (Winkler & Breaker, 2005). Ligand driven conformational change regulates translation either by sequestering ribosome binding site or by releasing it (Caron et al, 2012). Engineered riboswitches have been reported to be modular and work in dose dependent manner (Ceres et al, 2013; Dixon et al, 2010).