Despite a wealth of biochemical in vitro data on the HMGA proteins of various organisms, their biological role in chromatin is still not convincingly clarified. Current evidence suggests that HMG proteins serve a global role in chromatin by conferring a more “open” configuration to chromatin regions that are more accessible to transcriptional regulators (Bianchi and Agresti, 2005; Catez et al., 2004). In addition, there is massive evidence that HMGA proteins act as architectural factors that facilitate assembly of functional transcription factor complexes (enhanceosomes) at DNA target sites by various mechanisms. Several studies analysing altered expression levels of HMGA genes in animals have demonstrated that the chromosomal HMGA proteins have important cellular roles. Knock-out of the mouse HMGA1 gene revealed that HMGA1 is required for normal sperm development (Liu et al., 2003), and that disrupting the HMGA1 gene results in a decreased expression of the insulin receptor, largely impairing insulin signalling (Foti et al., 2005). Inactivation of the HMGA2 gene causes the mouse pygmy phenotype, and a deficiency in fat tissue, probably due to affected fat-cell proliferation (Anand and Chada, 2000; Zhou et al., 1995). Moreover, mouse HMGA2 is target of a regulatory miRNA and is involved in stem cell aging (Hammond and Sharpless, 2008).
Plant HMGA proteins bind A/T-rich DNA and they display high affinity for four-way junction DNA (Nieto-Sotelo et al., 1994; Webster et al., 1997; Zhang et al., 2003). Moreover, they specifically interact with nucleosome particles and are released from chromatin by limited nuclease digestion, suggesting preferential binding to transcriptionally active chromatin (Arwood and Spiker, 1990; Lichota and ...
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...odology is established in the Grasser-lab (Launholt et al., 2006; Pedersen et al., 2010; Pedersen et al., 2011).
WP4. Another approach to learn about the function of HMGA is the identification of protein interactors. Therefore, recombinant HMGA fused to gluthatione S transferase (GST) is immobilised (in parallel GST alone serves as control) and is incubated with nuclear protein extracts. Proteins that specifically bind GST-HMGA (but not GST) are identified by MALDI-TOF mass spectrometry that is perfomed at the Biochemistry Department at Regensburg University. In parallel, the existing HMGA antibody (Launholt et al., 2006) is used for immunoprecipitation of HMGA from plant protein extracts. Specifically coprecipitating proteins are again identified by mass spectrometry. The identification of interacting proteins will help elucidating the role of HMGA in Arabidopsis.
The first step of the experiment was ligation, and the objective was to insert EGFP cDNA into a restriction cut pET41a(+) vector to obtain a recombinant plasmid that would express green fluorescent gene. pET41a(+) was the choice of vector to ligate the EGFP into. Its structural design and genomic sequential properties render it especially well-suited for cloning and high-level expression of peptide sequences. This 5933 bp circular vector contains a built in sequence for Kanamayacin resistance gene. “Rooting of non-transgenic shoots was completely inhibited in all culture media containing kanamycin” (Montserrat, et. al., 2001). This allowed the growth of recombinant and non-recombinant colonies of E. coli, all of which contained the vector insert.
Figure 2 shows the results of the electrophoresis. Lanes 5 and 7 indicate the fragments obtained when the plasmids are digested with both restriction enzymes, indicating the approximate fragment size for the hlyA gene, the pK184 plasmid and the pBluescript plasmid. This is useful for identifying the recombinant DNA needed for this experiment
...It allowed access to virtually annotate sequences freely, build and visualize maps, design primers, and restriction analysis. First, the pEGFP-N1 plasmid nucleotide sequence was found by using the NCBI nucleotide database program. SnapGene viewer illustrated the restriction enzyme cut sites used to cut EGFP gene from the pEGFP-N1 source plasmid. Then the pET-41a (+) vector sequence was found by using the AddGene Vector Database. A new DNA file representing the recombinant pET-41a (+)-EGFP plasmid was built by virtually cloning the EGFP gene insert into the pET-41a (+) vector sequence. The plasmid was virtually cut utilizing the pAD1 sense primer and pAD1 anti primer from the PCR procedure. A restriction digest experiment was designed to confirm the identity of the PCR product. The two restriction endonucleases that cut the PCR product at least once was HgaI and XspI.
ABSTRACT: Chloroplasts carry out photosynthetic processes to meet the metabolic demands of plant cells (Alberts, 2008). They consist of an inner thylakoid membrane and a stroma. (Parent et. al, 2008).In this experiment we demonstrate the unique protein compositions of isolated thylakoid and stromal fractions from broken and whole spinach chloroplasts. Because these compartments carry out different metabolic processes, we confirm our hypothesis that performing SDS-PAGE on these fractions will result in distinct patterns on the gels. In isolating and analyzing nucleic acid from broken, whole, and crude chloroplast samples we demonstrate that genes for photosynthetic protein psbA are found in chloroplast DNA, while genes for photosynthetic enzyme
The ‘where visual pathway’ is concerned with constructing three dimensional representations of the environment and helps our brain to navigate where things are, independently of what they are, in space in relation to itself (Mishkin & Ungerleider & Macko, 1983).... ... middle of paper ... ... The 'Standard' of the 'Standard'.
...ormation Processing: The Nervous System." Biology: Life on Earth. 3rd ed. New York: Macmillan Publishing Company, 1993. 776- 805.
The unique insight brought by the ENCODE project has lead to several revolutionary ideas for the inter workings of genetics on the molecular scale; however, there has been much controversy over the projects findings throughout the scientific community. The ENCODE project states “The vast majority (80.4%) of the human genome participates in at least one biochemical RNA-and/or chromatin-associated event in at least one cell type” (The ENCODE Project Consortium). This statement claims the functionality of the human genome as a whole and is the core theme that will be analyzed.
All living things depend on a source of energy for their survival. These sources may vary from one species to another. For example, human’s and animal’s main source of energy is food, while plants main source of energy is sunlight. Plants lack the ability to move and look for sources of energy, runaway from predators, or avoid Abiotic stress. Instead, they have Photoreceptors such as chlorophyll found in plants’ chloroplasts which absorbs light and changes it into a cascade of electron transfer that serve as the main source of energy for plants. Moreover, different kinds of proteins regulate the plants life cycle such as phytochrome, cryptochromes, and phototropins. These proteins are mostly pigments that intercept light at different wavelengths and thus each photoreceptor is activated by different light conditions. Using their Photoreceptors, plants transform different light signals to regulate the plant’s growth, development, defense mechanisms, and stress responses. Most of the processes and mechanisms taking place in plant cells usually rely on signaling pathways. These signaling pathways depend on proteins that have different function in activating, inhibiting, or relying the signal from a protein to another. The most important proteins in these signaling pathways are kinases and phosphatases. Studies have recently shown important data that proves the interaction of these photoreceptors and some kinases and phosphatases, for example the interaction of phytochromes with PP2A phosphatases (Bissondial, 2005).
Sanderfoot, A., & Raikhel, N. (n.d.). The Specificity of Vesicle Trafficking: Coat Proteins and SNAREs. The Specificity of Vesicle Trafficking: Coat Proteins and SNAREs. Retrieved February 13, 2014, from http://www.plantcell.org/content/11/4/629.full
By utilizing, and, if possible, modifying this special DNA structure, one may see a reduction of age related illness, diseases, and signs of aging. In this review of human telomeres, we will discuss the roles and functions of the telomere, its structure, and the relation of telomere length to aging and tumorigenesis. Role and Functions of The Telomeres Telomeres are special DNA structures that consist of repetitive nucleotide sequences, which serve as a “cap” to protect the ends of the chromosomes. These repetitive sequences can range from thousands of base pairs in Vertebrates to about a few hundreds of base pairs in yeast cells (Oeseburg, et al. 2009). The 'Secondary' of the 'Secondary' of the 'Secondary' of the 'Secondary' of the 'Secondary' of the 'Secondary' of the 'Secondary' of the 'Secondary' of the 'Secondary' of the 'S Located at the ends of the chromosomes, the telomeres serve as a biological life line for cells.
As an inducer of HIF-1 production, it’s been used to study the apoptotic effects in HepG2 cells.
For example, some key plant proteins are often low in methionine, tryptophan, lycine and isoleucine.
In addition to this use of models, the natural sciences also use models to illustrate observations. When looking through a microscope one would need to model the cell or any such microscopic being, however it is impossible, as well as illogical, to grab wha...
Campbell, N. A. & J. B. Reece, 8th eds. (2008). Biology. San Francisco: Pearson Benjamin Cummings.
NHEJ functions in all the types of cells, from bacteria to man, and it carries out various functions such as repair of double stranded DNA breaks, telomere maintenance, and the insertion into the genome of HIV-1 and repetitive sequences. NHEJ seems to function in three main steps: 1) DNA end-binding and bridging, 2) terminal end processing, 3) and ligation of the two strands (http://www.ebi.ac.uk/interpro/potm/2004_7/Page2.htm). Another mechanism by which genes can be exchanged between related species is through – Introregression – that is, flow of genetic material as a result of interspecies hybridization followed by repeated backcrosses to any one of the parents. It is a major type of gene transfer mechanism in transgenic crops that are grown in proximity to non-domesticated relatives. However, it is not just restricted to plants. Introgression was believed to have intro¬duced an allele which is required in functional brain development from archaea to humans