|
Gag (gene)
Group-specific antigen, or gag, is the polyprotein that contains the core structural proteins of an Ortervirus (except ''Caulimoviridae''). It was named as such because scientists used to believe it was antigenic. Now it is known that it makes up the inner shell, not the envelope exposed outside. It makes up all the structural units of viral conformation and provides supportive framework for mature virion. All orthoretroviral ''gag'' proteins are processed by the protease (PR or ''pro'') into MA (matrix), CA (capsid), NC (nucleocapsid) parts, and sometimes more. If Gag fails to cleave into its subunits, virion fails to mature and remains uninfective. It comprises part of the ''gag-onc'' fusion protein. Gag in HIV Numbering system By convention, the HIV genome is numbered according to HIV-1 group M subtype B reference strain HXB2. Transcription and mRNA processing After a virus enters a target cell, the viral genome is integrated into the host cell chromatin. RNA polymer ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Polyprotein
Proteolysis is the breakdown of proteins into smaller polypeptides or amino acids. Protein degradation is a major regulatory mechanism of gene expression and contributes substantially to shaping mammalian proteomes. Uncatalysed, the hydrolysis of peptide bonds is extremely slow, taking hundreds of years. Proteolysis is typically catalysed by cellular enzymes called proteases, but may also occur by intra-molecular digestion. Proteolysis in organisms serves many purposes; for example, digestive enzymes break down proteins in food to provide amino acids for the organism, while proteolytic processing of a polypeptide chain after its synthesis may be necessary for the production of an active protein. It is also important in the regulation of some physiological and cellular processes including apoptosis, as well as preventing the accumulation of unwanted or misfolded proteins in cells. Consequently, abnormality in the regulation of proteolysis can cause diseases. Proteolysis can also ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Capsid
A capsid is the protein shell of a virus, enclosing its genetic material. It consists of several oligomeric (repeating) structural subunits made of protein called protomers. The observable 3-dimensional morphological subunits, which may or may not correspond to individual proteins, are called capsomeres. The proteins making up the capsid are called capsid proteins or viral coat proteins (VCP). The virus genomic component inside the capsid, along with occasionally present virus core protein, is called the virus core. The capsid and core together are referred to as a nucleocapsid (cf. also virion). Capsids are broadly classified according to their structure. The majority of the viruses have capsids with either helical or icosahedral structure. Some viruses, such as bacteriophages, have developed more complicated structures due to constraints of elasticity and electrostatics. The icosahedral shape, which has 20 equilateral triangular faces, approximates a sphere, while th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Metaviridae
''Metaviridae'' is a family of viruses which exist as Ty3-gypsy LTR retrotransposons in a eukaryotic host's genome. They are closely related to retroviruses: members of the family ''Metaviridae'' share many genomic elements with retroviruses, including length, organization, and genes themselves. This includes genes that encode reverse transcriptase, integrase, and capsid proteins. The reverse transcriptase and integrase proteins are needed for the retrotransposon activity of the virus. In some cases, virus-like particles can be formed from capsid proteins. Some assembled virus-like particles of members of the family ''Metaviridae'' can penetrate and infect previously uninfected cells. An example of this is the gypsy, a retroelement found in the ''Drosophila melanogaster'' genome. The ability to infect other cells is determined by the presence of the retroviral ''env'' genes which encode coat proteins. Metaviridae retrotransposons are found in all eukaryotes known and studied ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Spumaretrovirinae
''Spumaretrovirinae'', commonly called spumaviruses (, Latin for "foam") or foamyviruses, is a subfamily of the ''Retroviridae'' family. ICTVMaster Species List 2018a v1MSL including all taxa updates since the 2017 release. Fall 2018 (MSL #33) Spumaviruses are exogenous viruses that have specific morphology with prominent surface spikes. The virions contain significant amounts of double-stranded full-length DNA, and assembly is rather unusual in these viruses. Spumaviruses are unlike most enveloped viruses in that the envelope membrane is acquired by budding through the endoplasmic reticulum instead of the cytoplasmic membrane. Some spumaviruses, including the equine foamy virus (EFV), bud from the cytoplasmic membrane. Some examples of these viruses are simian foamy virus and the human foamy virus Humans (''Homo sapiens'') or modern humans are the most common and widespread species of primate, and the last surviving species of the genus ''Homo''. They are Hominidae, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Multiple Sclerosis
Multiple sclerosis (MS) is an autoimmune disease resulting in damage to myelinthe insulating covers of nerve cellsin the brain and spinal cord. As a demyelinating disease, MS disrupts the nervous system's ability to Action potential, transmit signals, resulting in a range of signs and symptoms, including physical, cognitive disability, mental, and sometimes psychiatric problems. Symptoms include double vision, vision loss, eye pain, muscle weakness, and loss of Sensation (psychology), sensation or coordination. MS takes several forms, with new symptoms either occurring in isolated attacks (relapsing forms) or building up over time (progressive forms). In relapsing forms of MS, symptoms may disappear completely between attacks, although some permanent neurological problems often remain, especially as the disease advances. In progressive forms of MS, bodily function slowly deteriorates once symptoms manifest and will steadily worsen if left untreated. While its cause is unclear, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Human Endogenous Retrovirus-W
Human Endogenous Retrovirus-W (HERV-W) is a family of Human Endogenous Retroviruses (HERVs). HERVs are part of a superfamily of repetitive and transposable elements. Transposable elements are sequences of DNA that can move or "jump" around the genome, sometimes replicating and inserting themselves in different locations. There are 31 known families of HERVs, constituting approximately about 8% of the human genome of which HERV-W DNA encoding sequences specifically account for about 1% of the human genome. For comparison, this represents about the same amount of DNA allocated to protein coding genes. Most HERVs in the genome today are not able to replicate, because of genetic changes such as frame shifts, premature stop codons, and recombination in their long terminal repeats (LTRs). Each HERV family is derived from a single infection of the human germline by an external retrovirus. After integrating into the human DNA, these retroviruses expanded and evolved over time. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Human Endogenous Retrovirus K
Human endogenous retrovirus K (HERV-K) or Human teratocarcinoma-derived virus (HDTV) is a family of human endogenous retroviruses associated with malignant tumors of the testes. Phylogenetically, the HERV-K group belongs to the ERV2 or Class II or Betaretrovirus-like supergroup. Over the past several years, it has been found that this group of ERVs play an important role in embryogenesis, but their expression is silenced in most cell types in healthy adults. The HERV-K family, and particularly its subgroup HML-2, is the youngest and most transcriptionally active group and hence, it is the best studied among other ERVs. Reactivation of it or anomalous expression of HML-2 in adult tissues has been associated with various types of cancer and with neurodegenerative diseases such as amytrophic lateral sclerosis (ALS). Endogenous retrovirus K (HERV-K) is related to Mouse mammary tumor virus, mammary tumor virus in mice. It exists in the human and cercopithecoid genomes. Human genome c ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
PDCD6IP
Programmed cell death 6-interacting protein also known as ALIX is a protein that in humans is encoded by the ''PDCD6IP'' gene. This gene encodes a protein thought to participate in programmed cell death. Studies using mouse cells have shown that overexpression of this protein can block apoptosis. In addition, the product of this gene binds to the product of the PDCD6 gene, a protein required for apoptosis, in a calcium-dependent manner. This gene product also binds to endophilins, proteins that regulate membrane shape during endocytosis. Overexpression of this gene product and endophilins results in cytoplasmic vacuolization which may be partly responsible for the protection against cell death. Function PDCD6IP protein is part of ESCRT pathway. It participates in the membrane scission of the revers topology budding and participates in multivesicular body formation. It is also vital at the later stages and for successful completion of cytokinesis. Interactions PDCD6IP has been s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
ESCRT-I
The endosomal sorting complexes required for transport (ESCRT) proteins are part of a group of machines inside cells that help sort and move other proteins. One of their main jobs is to form structures called multivesicular bodies (MVBs) which help sending of certain proteins, especially ones tagged for removal to compartments in the cell called lysosomes where they get broken down. The ESCRT system is made up of five separate cytosolic protein complexes, known as ESCRT-0, ESCRT-I, ESCRT-II, ESCRT-III and Vps4. and each one has specific job. Together with a number of accessory proteins, these ESCRT complexes enable a unique mode of membrane remodeling that results in membranes bending/budding away from the cytoplasm. These ESCRT components have been isolated and studied in a number of organisms including yeast and humans. The ESCRT machinery plays a vital role in a number of cellular processes including multivesicular body (MVB) biogenesis and Cytokinetic abscission. Multivesicula ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
TSG101
Tumor susceptibility gene 101, also known as TSG101, is a human gene that encodes for a cellular protein of the same name. Function The protein encoded by this gene belongs to a group of apparently inactive homologs of ubiquitin-conjugating enzymes. The gene product contains a coiled-coil domain that interacts with stathmin, a cytosolic phosphoprotein implicated in tumorigenesis. The protein may play a role in cell growth and differentiation and act as a negative growth regulator. In vitro steady-state expression of this tumor susceptibility gene appears to be important for maintenance of genomic stability and cell cycle regulation. Mutations and alternative splicing in this gene occur in high frequency in breast cancer and suggest that defects occur during breast cancer tumorigenesis and/or progression. The main role of TSG101 is to participate in ESCRT pathway. This pathway facilitates reverse topology budding and formation of multivesicular bodies (MVB) which delivers cargo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Alpha Helix
An alpha helix (or α-helix) is a sequence of amino acids in a protein that are twisted into a coil (a helix). The alpha helix is the most common structural arrangement in the Protein secondary structure, secondary structure of proteins. It is also the most extreme type of local structure, and it is the local structure that is most easily predicted from a sequence of amino acids. The alpha helix has a right-handed helix conformation in which every backbone amino, N−H group hydrogen bonds to the backbone carbonyl, C=O group of the amino acid that is four residue (biochemistry), residues earlier in the protein sequence. Other names The alpha helix is also commonly called a: * Pauling–Corey–Branson α-helix (from the names of three scientists who described its structure) * 3.613-helix because there are 3.6 amino acids in one ring, with 13 atoms being involved in the ring formed by the hydrogen bond (starting with amidic hydrogen and ending with carbonyl oxygen) Discovery ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lentiviral Vector In Gene Therapy
Lentiviral vectors in gene therapy is a method by which genes can be inserted, modified, or deleted in organisms using lentiviruses. Lentiviruses are a family of viruses that are responsible for diseases like AIDS, which infect by inserting DNA into their host cells' genome. Many such viruses have been the basis of research using viruses in gene therapy, but the lentivirus is unique in its ability to infect non-dividing cells, and therefore has a wider range of potential applications. Lentiviruses can become endogenous (ERV), integrating their genome into the host germline genome, so that the virus is henceforth inherited by the host's descendants. Scientists use the lentivirus' mechanisms of infection to achieve a desired outcome to gene therapy. Lentiviral vectors in gene therapy have been pioneered by Luigi Naldini. The lentivirus is a retrovirus, meaning it has a single stranded RNA genome with a reverse transcriptase enzyme. Lentiviruses also have a viral envelope with prot ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
