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Fibrillin-1
Fibrillin-1 is a protein that in humans is encoded by the ''FBN1'' gene, located on chromosome 15. It is a large, extracellular matrix glycoprotein that serves as a structural component of 10-12 nm calcium-binding microfibrils. These microfibrils provide force bearing structural support in elastic and nonelastic connective tissue throughout the body. Mutations altering the protein can result in a variety of phenotypic effects differing widely in their severity, including fetal death, developmental problems, Marfan syndrome or in some cases Weill-Marchesani syndrome. ''FBN1'' gene ''FBN1'' is a 230-kb gene with 65 coding exons that encode a 2,871-amino-acid long proprotein called profibrillin which is proteolytically cleaved near its C-terminus by the enzyme furin convertase to give fibrillin-1, a member of the fibrillin family, and the 140-amino-acid long protein hormone asprosin. FBN-1 protein structure The sequence of fibrillin-1 includes 47 six-cysteine EGF-like domain ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
EGF-like Domain
The EGF-like domain is an evolutionary conserved protein domain, which derives its name from the epidermal growth factor where it was first described. It comprises about 30 to 40 amino-acid residues and has been found in a large number of mostly animal proteins. Most occurrences of the EGF-like domain are found in the extracellular domain of membrane-bound proteins or in proteins known to be secreted. An exception to this is the prostaglandin-endoperoxide synthase. The EGF-like domain includes 6 cysteine residues which in the epidermal growth factor have been shown to form 3 disulfide bonds. The structures of 4-disulfide EGF-domains have been solved from the laminin and integrin proteins. The main structure of EGF-like domains is a two-stranded β-sheet followed by a loop to a short C-terminal, two-stranded β-sheet. These two β-sheets are usually denoted as the major (N-terminal) and minor (C-terminal) sheets. EGF-like domains frequently occur in numerous tandem copies in pro ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Asprosin
Asprosin is a protein hormone produced by mammals in ( white adipose) tissues that stimulates the liver to release glucose into the blood stream. Asprosin is encoded by the gene ''FBN1'' as part of the protein profibrillin and is released from the C-terminus of the latter by specific proteolysis. In the liver, asprosin activates rapid glucose release via a cyclic adenosine monophosphate (cAMP)-dependent pathway. Discovery Asprosin was first identified by Dr. Atul Chopra and coworkers at Baylor College of Medicine as a C-terminal cleavage product of the ''FBN1'' gene product profibrillin. They found mutations in the ''FBN1'' gene in two patients with congenital partial lipodystrophy and a progeroid appearance. The two patients were Lizzie Velasquez and Abby Solomon. Truncations of the FBN1 protein in these patients were seen to have two consequences for protein production: a mutant/truncated fibrillin protein and very low plasma asprosin levels (from a postulated dominant ne ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fibrillin
Fibrillin is a glycoprotein, which is essential for the formation of elastic fibers found in connective tissue. Fibrillin is secreted into the extracellular matrix by fibroblasts and becomes incorporated into the insoluble microfibrils, which appear to provide a scaffold for deposition of elastin. Clinical aspects Marfan syndrome is a genetic disorder of the connective tissue caused by defected FBN1 gene. Mutations in FBN1 and FBN2 are also sometimes associated with adolescent idiopathic scoliosis. Types Fibrillin-1 Fibrillin-1 is a major component of the microfibrils that form a sheath surrounding the amorphous elastin. It is believed that the microfibrils are composed of end-to-end polymers of fibrillin. To date, 3 forms of fibrillin have been described. The fibrillin-1 protein was isolated by Engvall in 1986, and mutations in the FBN1 gene cause Marfan syndrome. This protein is found in humans, and its gene is found on chromosome 15. At present more than 1500 differe ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fibrillin
Fibrillin is a glycoprotein, which is essential for the formation of elastic fibers found in connective tissue. Fibrillin is secreted into the extracellular matrix by fibroblasts and becomes incorporated into the insoluble microfibrils, which appear to provide a scaffold for deposition of elastin. Clinical aspects Marfan syndrome is a genetic disorder of the connective tissue caused by defected FBN1 gene. Mutations in FBN1 and FBN2 are also sometimes associated with adolescent idiopathic scoliosis. Types Fibrillin-1 Fibrillin-1 is a major component of the microfibrils that form a sheath surrounding the amorphous elastin. It is believed that the microfibrils are composed of end-to-end polymers of fibrillin. To date, 3 forms of fibrillin have been described. The fibrillin-1 protein was isolated by Engvall in 1986, and mutations in the FBN1 gene cause Marfan syndrome. This protein is found in humans, and its gene is found on chromosome 15. At present more than 1500 differe ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Marfan Syndrome
Marfan syndrome (MFS) is a multi-systemic genetic disorder that affects the connective tissue. Those with the condition tend to be tall and thin, with long arms, legs, fingers, and toes. They also typically have exceptionally flexible joints and abnormally curved spines. The most serious complications involve the heart and aorta, with an increased risk of mitral valve prolapse and aortic aneurysm. The lungs, eyes, bones, and the covering of the spinal cord are also commonly affected. The severity of the symptoms is variable. MFS is caused by a mutation in ''FBN1'', one of the genes that makes fibrillin, which results in abnormal connective tissue. It is an autosomal dominant disorder. In about 75% of cases, it is inherited from a parent with the condition, while in about 25% it is a new mutation. Diagnosis is often based on the Ghent criteria. There is no known cure for MFS. Many of those with the disorder have a normal life expectancy with proper treatment. Management oft ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Microfibril
A microfibril is a very fine fibril, or fiber-like strand, consisting of glycoproteins and cellulose. It is usually, but not always, used as a general term in describing the structure of protein fiber, e.g. hair and sperm tail. Its most frequently observed structural pattern is the 9+2 pattern in which two central protofibrils are surrounded by nine other pairs. Cellulose inside plants is one of the examples of non-protein compounds that are using this term with the same purpose. Cellulose microfibrils are laid down in the inner surface of the primary cell wall. As the cell absorbs water, its volume increases and the existing microfibrils separate and new ones are formed to help increase cell strength. Synthesis and function Cellulose is synthesized by cellulose synthase or Rosette terminal complexes which reside on a cells membrane. As cellulose fibrils are synthesized and grow extracellularly they push up against neighboring cells. Since the neighboring cell can not move easily t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Marfan Syndrome
Marfan syndrome (MFS) is a multi-systemic genetic disorder that affects the connective tissue. Those with the condition tend to be tall and thin, with long arms, legs, fingers, and toes. They also typically have exceptionally flexible joints and abnormally curved spines. The most serious complications involve the heart and aorta, with an increased risk of mitral valve prolapse and aortic aneurysm. The lungs, eyes, bones, and the covering of the spinal cord are also commonly affected. The severity of the symptoms is variable. MFS is caused by a mutation in ''FBN1'', one of the genes that makes fibrillin, which results in abnormal connective tissue. It is an autosomal dominant disorder. In about 75% of cases, it is inherited from a parent with the condition, while in about 25% it is a new mutation. Diagnosis is often based on the Ghent criteria. There is no known cure for MFS. Many of those with the disorder have a normal life expectancy with proper treatment. Management of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
FBN2
Fibrillin is a glycoprotein, which is essential for the formation of elastic fibers found in connective tissue. Fibrillin is secreted into the extracellular matrix by fibroblasts and becomes incorporated into the insoluble microfibrils, which appear to provide a scaffold for deposition of elastin. Clinical aspects Marfan syndrome is a genetic disorder of the connective tissue caused by defected FBN1 gene. Mutations in FBN1 and FBN2 are also sometimes associated with adolescent idiopathic scoliosis. Types Fibrillin-1 Fibrillin-1 is a major component of the microfibrils that form a sheath surrounding the amorphous elastin. It is believed that the microfibrils are composed of end-to-end polymers of fibrillin. To date, 3 forms of fibrillin have been described. The fibrillin-1 protein was isolated by Engvall in 1986, and mutations in the FBN1 gene cause Marfan syndrome. This protein is found in humans, and its gene is found on chromosome 15. At present more than 1500 differen ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
MASS Phenotype
MASS syndrome is a medical disorder of the connective tissue similar to Marfan syndrome. MASS stands for: Mitral valve prolapse, Aortic root diameter at upper limits of normal for body size, Stretch marks of the skin, and Skeletal conditions similar to Marfan syndrome. It is caused by a mutation in the ''FBN1'' gene, which encodes fibrillin-1. Fibrillin-1 is an extracellular matrix protein that is found in microfibrils; defects in the fibrillin-1 protein cause the malfunctioning of microfibrils, which results in improper stretching of ligaments, blood vessels, and skin. Treatment options for MASS syndrome are largely determined on a case-by-case basis and generally address the symptoms as opposed to the actual disorder; furthermore, due to the similarities between these two disorders, individuals with MASS syndrome follow the same treatment plans as those with Marfan syndrome. Other possible symptoms are mitral valve prolapse, a large aortic root diameter, and myopia. The ske ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Chromosome 15
Chromosome 15 is one of the 23 pairs of chromosomes in humans. People normally have two copies of this chromosome. Chromosome 15 spans about 102 million base pairs (the building material of DNA) and represents between 3% and 3.5% of the total DNA in cells. Chromosome 15 is an acrocentric chromosome, with a very small short arm (the "p" arm, for "petite"), which contains few protein coding genes among its 19 million base pairs. It has a larger long arm (the "q" arm) that is gene rich, spanning about 83 million base pairs. The human leukocyte antigen gene for β2-microglobulin is found on chromosome 15, as well as the FBN1 gene, coding for both fibrillin-1 (a protein critical to the proper functioning of connective tissue), and aprosin (a small protein produced from part of the transcribed FBN1 gene mRNA), which is involved in fat metabolism. Genes Number of genes The following are some of the gene count estimates of human chromosome 15. Because researchers use different approac ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Marfanoid–progeroid–lipodystrophy Syndrome
Marfanoid–progeroid–lipodystrophy syndrome (MPL), also known as Marfan lipodystrophy syndrome (MFLS) or progeroid fibrillinopathy, is an extremely rare medical condition which manifests as a variety of symptoms including those usually associated with Marfan syndrome, an appearance resembling that seen in neonatal progeroid syndrome (NPS; also known as Wiedemann–Rautenstrauch syndrome), and severe partial lipodystrophy. It is a genetic condition that is caused by mutations in the ''FBN1'' gene, which encodes profibrillin, and affects the cleavage products of profibrillin, fibrillin-1, a fibrous structural protein, and asprosin, a glucogenic protein hormone. As of 2016, fewer than 10 cases of the condition have been reported. Lizzie Velásquez and Abby Solomon have become known publicly through the media for having the condition. In addition to severe lipodystrophy (loss of adipose tissue), individuals with MPL show a concomitant marked loss of lean tissue mass, which ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ectopia Lentis
Ectopia lentis is a displacement or malposition of the eye's crystalline lens from its normal location. A partial dislocation of a lens is termed lens subluxation or subluxated lens; a complete dislocation of a lens is termed lens luxation or luxated lens. Ectopia lentis in dogs and cats Although observed in humans and cats, ectopia lentis is most commonly seen in dogs. Ciliary zonules normally hold the lens in place. Abnormal development of these zonules can lead to primary ectopia lentis, usually a bilateral condition. Luxation can also be a secondary condition, caused by trauma, cataract formation (decrease in lens diameter may stretch and break the zonules), or glaucoma (enlargement of the globe stretches the zonules). Steroid administration weakens the zonules and can lead to luxation, as well. Lens luxation in cats can occur secondary to anterior uveitis (inflammation of the inside of the eye). Anterior lens luxation With anterior lens luxation, the lens pushes into the i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
