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CFHR5
Complement factor H-related protein 5 is a protein that in humans is encoded by the ''CFHR5'' gene. Function CFHR5 is structurally related to complement factor H which plays an important role in the regulation of a branch of the innate immune system called the alternative complement pathway. Like complement factor H, CFHR5 is able to bind to complement C3. Clinical Significance A mutation in CHFR5 was found in patients with the disease CFHR5 nephropathy, which is a common cause of renal disease in Cyprus. The mutated form of the protein found in patients with this disease has impaired ability to bind to complement C3, suggesting that CFHR5 is important in protecting the kidneys from attack by the complement system The complement system, also known as complement cascade, is a part of the immune system that enhances (complements) the ability of antibodies and phagocytic cells to clear microbes and damaged cells from an organism, promote inflammation, and at .... References Ex ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
CFHR5 Nephropathy
Complement factor H-related protein 5 (CFHR5) nephropathy is a form of inherited kidney disease which is endemic in Cyprus and is caused by a mutation in the gene CFHR5. It is thought to affect up to 1:6000 Cypriots but has not been reported in anybody who is not of Cypriot descent. Presentation Sometimes the disease is associated with visible blood in the urine, usually at the time of respiratory or other infections and this is thought to result from stimulation of the immune system leading to damage in the kidneys. Diagnosis The diagnosis can be confirmed on a blood sample using a genetic test. CFHR5 nephropathy usually presents with microscopic amounts of blood in the urine, detectable on a routine urine dipstick test. Biopsy findings A kidney biopsy in patients with CFHR5 nephropathy classically shows deposition of complement C3 in the kidney, without any detectable immunoglobulins there. This is evidence that the disease is caused by a problem with alternative complement pa ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Alternative Complement Pathway
The alternative pathway is a type of cascade reaction of the complement system and is a component of the innate immune system, a natural defense against infections. The alternative pathway is one of three complement pathways that opsonize and kill pathogens. The pathway is triggered when the C3b protein directly binds a microbe. It can also be triggered by foreign materials and damaged tissues. Cascade This change in shape allows the binding of plasma protein Factor B, which allows Factor D to cleave Factor B into Ba and Bb. Bb remains bound to C3(H2O) to form C3(H2O)Bb. This complex is also known as a fluid-phase C3-convertase. This convertase, the alternative pathway C3-convertase, although only produced in small amounts, can cleave multiple C3 proteins into C3a and C3b. The complex is believed to be unstable until it binds properdin, a serum protein. The addition of properdin forms the complex C3bBbP, a stable compound which can bind an additional C3b to form alternativ ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Protein
Proteins are large biomolecules and macromolecules that comprise one or more long chains of amino acid residues. Proteins perform a vast array of functions within organisms, including catalysing metabolic reactions, DNA replication, responding to stimuli, providing structure to cells and organisms, and transporting molecules from one location to another. Proteins differ from one another primarily in their sequence of amino acids, which is dictated by the nucleotide sequence of their genes, and which usually results in protein folding into a specific 3D structure that determines its activity. A linear chain of amino acid residues is called a polypeptide. A protein contains at least one long polypeptide. Short polypeptides, containing less than 20–30 residues, are rarely considered to be proteins and are commonly called peptides. The individual amino acid residues are bonded together by peptide bonds and adjacent amino acid residues. The sequence of amino acid residue ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gene
In biology, the word gene (from , ; "...Wilhelm Johannsen coined the word gene to describe the Mendelian units of heredity..." meaning ''generation'' or ''birth'' or ''gender'') can have several different meanings. The Mendelian gene is a basic unit of heredity and the molecular gene is a sequence of nucleotides in DNA that is transcribed to produce a functional RNA. There are two types of molecular genes: protein-coding genes and noncoding genes. During gene expression, the DNA is first copied into RNA. The RNA can be directly functional or be the intermediate template for a protein that performs a function. The transmission of genes to an organism's offspring is the basis of the inheritance of phenotypic traits. These genes make up different DNA sequences called genotypes. Genotypes along with environmental and developmental factors determine what the phenotypes will be. Most biological traits are under the influence of polygenes (many different genes) as well as gen ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Factor H
Factor H is a member of the regulators of complement activation family and is a complement control protein. It is a large (155 kilodaltons), soluble glycoprotein that circulates in human plasma (at typical concentrations of 200–300 micrograms per milliliter). Its principal function is to regulate the alternative pathway of the complement system, ensuring that the complement system is directed towards pathogens or other dangerous material and does not damage host tissue. Factor H regulates complement activation on self cells and surfaces by possessing both cofactor activity for the Factor I mediated C3b cleavage, and decay accelerating activity against the alternative pathway C3-convertase, C3bBb. Factor H exerts its protective action on self cells and self surfaces but not on the surfaces of bacteria or viruses. This is thought to be the result of Factor H having the ability to adopt conformations with lower or higher activities as a cofactor for C3 cleavage or decay accelerat ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Complement Component 3
Complement component 3, often simply called C3, is a protein of the immune system. It plays a central role in the complement system and contributes to innate immunity. In humans it is encoded on chromosome 19 by a gene called ''C3''. Function C3 plays a central role in the activation of the complement system. Its activation is required for both classical and alternative complement activation pathways. People with C3 deficiency are susceptible to bacterial infection. One form of C3-convertase, also known as C4b2a, is formed by a heterodimer of activated forms of C4 and C2. It catalyzes the proteolytic cleavage of C3 into C3a and C3b, generated during activation through the classical pathway as well as the lectin pathway. C3a is an anaphylotoxin and the precursor of some cytokines such as ASP, and C3b serves as an opsonizing agent. Factor I can cleave C3b into C3c and C3d, the latter of which plays a role in enhancing B cell responses. In the alternative complement pathway, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cyprus
Cyprus ; tr, Kıbrıs (), officially the Republic of Cyprus,, , lit: Republic of Cyprus is an island country located south of the Anatolian Peninsula in the eastern Mediterranean Sea. Its continental position is disputed; while it is geographically in Western Asia, its cultural ties and geopolitics are overwhelmingly Southern European. Cyprus is the third-largest and third-most populous island in the Mediterranean. It is located north of Egypt, east of Greece, south of Turkey, and west of Lebanon and Syria. Its capital and largest city is Nicosia. The northeast portion of the island is ''de facto'' governed by the self-declared Turkish Republic of Northern Cyprus, which was established after the 1974 invasion and which is recognised as a country only by Turkey. The earliest known human activity on the island dates to around the 10th millennium BC. Archaeological remains include the well-preserved ruins from the Hellenistic period such as Salamis and Kourion, and Cypr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
