The flu is characterized as an infection of the respiratory tract caused by influenza viruses. Influenza A, B and C viruses belong to the Orthomyxovirus, which is the family of enveloped viruses with segmented, single-stranded, negative-sense RNA genome (Calder et al., 2010; Cox & Subbarao, 1999). Influenza A virus is the most virulent human pathogen among the three types because they can infect both animals and human, causing of all the major flu pandemics in modern history.
Influenza A virus, unlike most RNA viruses, transcribes and replicates its genome in the nucleus. This nuclear site for replication is likely due to the requirement for cellular splicing machinery and polymerase present there. The influenza A virus genome consists of
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Initiation of nuclear import of the vRNP complex is triggered by recognition of NLSs on the NP by impotin α/importin β (Cros et al., 2005; O'Neill et al., 1995). Previous studies have shown that NP contains at least two NLSs. The unconventional NLS (NLS1) locates at the N-terminus (Wang et al., 1997). The second NLS is a bipartite signal (NLS 2) located in the middle of NP (Weber et al., 1998). In spite of a great amount work that has been done on the notable of nuclear import, the contribution of NLS1 and NLS2 to the nuclear import of vRNPs and newly synthesis NPs has been the subject of much …show more content…
Pante laboratory shown that NLS2 alone could mediate nuclear import of vRNP using antibody inhibition assay and peptide competition experiments, suggesting that NLS2 could potentially be an important factor during the nuclear entry of the viral genome (Wu et al., 2007b). Recently, Ketha and Atreya, (2008) have demonstrated that a third overlapping bipartite NLS (obp NLS) locates at amino acid 90-121 using a bioinformatics analysis. They proved that the chimeric proteins are transported into nucleus in the presence of this obp NLS when it fused to GFP. Also, it is possible that natural-occurring of influenza-assembled vRNP may behave differently compared to in vitro-derived ones. Previous studies have concentrated mainly on the nuclear import using in vitro-assembled RNPs, which may differ structurally from influenza-assembled vRNP complexes within mammalian cells. Hence, a natural-occurring infection system is critical to determine the role of NLS1 and NLS2 during influenza A virus
Scibd. N.p. Web. 17 Mar 2014. Beller, Michele.
Like other negative-stranded RNA viruses, the G protein of rabies virus binds to the host cell membranes and penetrates into the host cytoplasm by pinocytosis. The virions are composed of cytoplasmic vesicles, fuse to cytoplasmic membrane and release RNP into the cytoplasm. The core starts primary transcription of the five complementary monocistronic messenger RNAs by using the virion-associated RNA-dependent RNA polymerase. Each mRNA is translated to an individual viral protein. After synthesis and replication of the genomic RNA, the full length, positive-stranded RNA is completed and becomes the template for the next negative-stranded RNA. In the assembly process, the N-P-L complex encapsulates negative-stranded genomic RNA to be made up of RNP core and the M protein consists of a capsule or matrix that su...
The Influenza virus is a unique respiratory viral disease that can have serious economic and social disruption to society. The virus is airborne transmitted through droplets release by coughing or sneezing from an infected person or by touching infected surfaces. Symptoms range from mild to severe and may even result in death. People with the virus usually experience fever, headache, shivering, muscle pain and cough, which can lead to more severe respiratory illness such as pneumonia. People most susceptible to the flu virus are elderly individuals and young children as well as anyone whose health or immune system has been compromise. The most effective way to counteract the influenza virus is to get the flu vaccine which is available by shots or nasal spray before the flu season as well as practicing safe hygiene. (CDC, 2013)
Loo, Yueh-Ming and Michael Gale, Jr. “Influenza: Fatal Immunity and the 1918 Virus.” Nature 445 (2007): 267-268. 23 July. 2008 .
The influenza virus is an enveloped virus that contains a genome of eight genes that define what the virus is. Everything begins when the virus enters the airways. Here, influenza viruses specifically attach to the surface of epithelial cells. The viral membrane envelope contains the neuraminidase (NA) protein, which is important for the efficient release of newly produced viruses. It also contains the matrix 2 (M2) ion channel that promotes viral structural changes during cellular entry as well as the influenza hemagglutinin (HA) protein, the key player for viral internalization, which facilitates viral binding to sialic acid decorated receptors on host cells, causing adsorption to the host cell (Samji, p. 3). Barry compares the HA proteins to little spikes and the NA proteins to tiny trees that both protrude all around the surface of the virus (p. 103). When the HA protein spikes come into contact with the sialic acid molecules, both structures bind to one another. Once this binding holds the virus and host cell together, the virus has achieved its first task of adsorption. Next, the virus particles are internalized into endosomes by clathrin mediated endocytosis. The pH of the endosomes drops tr...
Influenza is a major public health problem which has outbreaks all over the world. Resulting in considerable sickness and death rates. Furthermore, it is a highly infectious airborne disease and is caused by the influenza virus. Influenza is transmitted easily from one person to another person, which has a great impact on society. When a member of society becomes sick, it is more prone to spread to other people.
The influenza pandemic of 1918-1919 killed more people than the Great War, known today as World War I (WWI), at somewhere between twenty and forty million people. (1) Influenza is a virus that appeared in 1918 and caused a pandemic. It made an enormous impact that is still significant to the world today. It has pushed scientists to make advancements in the medicine and vaccination industry that continue to grow each and every day. Influenza may be a horrible thing, but without it we wouldn’t be where we are today.
Influenza or flu is caused by RNA viruses of the family orthomyxoviridae, that affects the nose, throat, and lungs- the respiratory system. The common symptoms are: fever and respiratory problems, such as cough, sore throat,stuffy nose, as well as headaches and muscle aches. Influenza viruses are spread mainly by droplets made from people coughing, sneezing or talking while having the flu. These droplets can land in the mouths or noses of people or can inhaled into the lungs. It is least common for the virus to spread by touching an infected surface then their mouth or nose. Flu viruses are divided into 3 categories, A, B, C. A and B are responsible for problems in the respiratory system that typically occurs during the winter. Influenza types C is quite different from A and B. Type C only cause mild respiratory symptom or none at all.
During the summer of 2013 I began a project with my Physics Department in the field of nuclear science under the guidance of Dr. Mohammad Hannan. The project, an analysis of samples from a local canal via Neutron Activation Analysis (NAA), was a joint investigation between The University of Texas Pan American (UTPA) and The University of California Irvine (UCI). A
In order to decide whether or not the swine flu vaccine is completely necessary, one must first gain a better understanding of the topic. It is a scientifically known fact that the swine flu is a result of a virus. A virus is a capsule of genetic material that causes infection in the body. The infectious particles are made up of nucleic acid enclosed in a protein shell, called a capsid. It cannot be considered a living organism like the disease causing agent of bacteria, because it does not carry out all the characteristics of life. Specifically, it cannot reproduce on its own.
The swine influenza or swine flu is a respiratory disease in pigs that is caused by the type A influenza viruses. These viruses are referred to as swine flu viruses but scientifically the main virus is called the swine triple reassortant (tr) H1N1 influenza virus. When the viruses infect humans they are called variant viruses. This infection has been caused in humans mainly by the H1N1v virus in the United States. The H1N1 virus originates in animals due to improper conditions and the food they ingest. The virus stays in latency form, thus harmless to the respective animal. The longer the animals survive the more likely the virus is to develop and strengthen making it immune to vaccines. The virus reproduced through the lytic cycle. The virus injects its own nucleic acids into a host cell and then they form a circle in the center of the cell. Rather than copying its own nucleic acids, the cell will copy the viral acids. The copies of viral acids then organize themselves as viruses inside of the cell. The membrane will eventually split leaving the viruses free to infect other cells.
The Flu is the common name influenza which is a virus that attacks the respiratory system. The flu virus releases its genetic information into the cells nucleus to replicate itself. When the cell dies, those copies are released and they affect other cells throughout the rest of the body. With that happening the virus weakens the immune system. When your sick with the flu, your body builds up a defense by making antibodies against it. The flu virus spreads through air when a person coughs, sneezes, or speaks.
Schreuder, Jolanda A. H.; Roelen, Corné A. M.; van Zweeden, Nely F.; Jongsma, Dianne; van der Klink, Jac J. L.; Groothoff, Johan W.
A previous study, looked at by the researchers, stated that nuclear localization signals are what allow the RNA to enter the nucleus (Wu W, Pante N. 2009). This persuaded them to ask the question of whether or not there was a nuclear localization signal within a viral protein of HCRSV. The localization of P23 was then tested using a transient expression method. The results of their experiment showed that there was a strong signal detected in the nucleus of the Kenaf leaf samples. This proved that P23 was in fact localized in the nucleus and that a nuclear localization signal is present in P23 (Gao R, Liu P, Wong SM. 2012). It was also found that P23 has the ability to bind to carrier proteins that come into the nucleus. This showed that even if P23 was not localized in the nucleus, it could still enter. The mode of entry into the nucleus was discovered to by α-importin (Gao R, Liu P, Wong SM. 2012) . This was discovered by experimenting with a probe of anti-importin α antibody. α-importin was only detected in the protein extract of P23 in the nucleus of the HCRSV-infected Kenaf sample (Gao R, Liu P, Wong SM. 2012). Researchers concluded from their results of the experiments that α-importin, P23, and HCRSV RNA form a complex that enters the nucleus to begin replication of the
...ound in our bodies. The trick is that the virus “gets confused” and incorporates the fatal molecule into its growing RNA strands which leads to the prevention of RNA synthesis and thus the entire viral replication.