Fibrillin
Encyclopedia
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
.
It forms microfilament
s.
is a major component of the microfibril
s that form a sheath surrounding the amorphous elastin
. It is believed that the microfibril
s are composed of end-to-end polymer
s 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 genes are found on chromosome 15. At present more than 600 different mutations have been described.
.
Glycoprotein
Glycoproteins are proteins that contain oligosaccharide chains covalently attached to polypeptide side-chains. The carbohydrate is attached to the protein in a cotranslational or posttranslational modification. This process is known as glycosylation. In proteins that have segments extending...
, which is essential for the formation of elastic fibers found in connective tissue
Connective tissue
"Connective tissue" is a fibrous tissue. It is one of the four traditional classes of tissues . Connective Tissue is found throughout the body.In fact the whole framework of the skeleton and the different specialized connective tissues from the crown of the head to the toes determine the form of...
.
Fibrillin is secreted into the extracellular matrix
Extracellular matrix
In biology, the extracellular matrix is the extracellular part of animal tissue that usually provides structural support to the animal cells in addition to performing various other important functions. The extracellular matrix is the defining feature of connective tissue in animals.Extracellular...
by fibroblasts and becomes incorporated into the insoluble microfibrils, which appear to provide a scaffold
for deposition of elastin
Elastin
Elastin is a protein in connective tissue that is elastic and allows many tissues in the body to resume their shape after stretching or contracting. Elastin helps skin to return to its original position when it is poked or pinched. Elastin is also an important load-bearing tissue in the bodies of...
.
It forms microfilament
Microfilament
Microfilaments are the thinnest filaments of the cytoskeleton, a structure found in the cytoplasm of all eukaryotic cells. These linear polymers of actin subunits are flexible and relatively strong, resisting buckling by multi-piconewton compressive forces and filament fracture by nanonewton...
s.
Fibrillin-1
Fibrillin-1FBN1
Fibrillin-1 is a protein that in humans is encoded by the FBN1 gene.This gene encodes a member of the fibrillin family. The encoded protein is a large, extracellular matrix glycoprotein that serve as a structural component of 10-12 nm calcium-binding microfibrils...
is a major component of the microfibril
Microfibril
The 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, examples are hair and sperm tail. Its most frequently observed structural pattern is 9+2...
s that form a sheath surrounding the amorphous elastin
Elastin
Elastin is a protein in connective tissue that is elastic and allows many tissues in the body to resume their shape after stretching or contracting. Elastin helps skin to return to its original position when it is poked or pinched. Elastin is also an important load-bearing tissue in the bodies of...
. It is believed that the microfibril
Microfibril
The 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, examples are hair and sperm tail. Its most frequently observed structural pattern is 9+2...
s are composed of end-to-end polymer
Polymer
A polymer is a large molecule composed of repeating structural units. These subunits are typically connected by covalent chemical bonds...
s 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
Marfan syndrome
Marfan syndrome is a genetic disorder of the connective tissue. People with Marfan's tend to be unusually tall, with long limbs and long, thin fingers....
.
This protein is found in humans, and its genes are found on chromosome 15. At present more than 600 different mutations have been described.
Structure
There is no complete, high-resolution structure of fibrillin-1. Instead, short fragments have been produced recombinantly and their structures solved by X-ray crystallography or using NMR spectroscopy. A recent example is the structure of the fibrillin-1 hybrid2 domain, in context of its flanking calcium binding epidermal growth factor domains, which was determined using X-ray crystallography to a resolution of 1.8 Å. The microfibrils that are made up of fibrillin protein are responsible for different cell-matrix interactions in the human body.Fibrillin-2
Fibrillin-2 was isolated in 1994 by Zhang and is thought to play a role in early elastogenesis. Mutations in the fibrillin-2 gene have been linked to Beal's SyndromeBeals syndrome
Beals syndrome is a rare congenital connective tissue disorder. Beals syndrome has only recently been described as a syndrome distinct from Marfan's Syndrome.It was characterized in 1972....
.