Complement factor H-related protein 5 is a
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, respo ...
that in humans is encoded by the ''CFHR5''
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 ba ...
.
Function
CFHR5 is structurally related to
complement 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 microgra ...
which plays an important role in the regulation of a branch of the innate immune system called the
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 k ...
. Like complement factor H, CFHR5 is able to bind to
complement C3
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
C ...
.
Clinical Significance
A mutation in CHFR5 was found in patients with the disease
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 an ...
, which is a common cause of renal disease in
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 geo ...
. 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
External links
GeneReviews/NCBI/NIH/UW entry on Dense Deposit Disease/Membranoproliferative Glomerulonephritis Type II*
Further reading
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