Dehydrodolichyl diphosphate synthase is an

enzyme Enzymes () are proteins that act as biological catalysts by accelerating chemical reactions. The molecules upon which enzymes may act are called substrates, and the enzyme converts the substrates into different molecules known as products ...

that in humans is encoded by the ''DHDDS''

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 b ...

Function

Dehydrodolichyl diphosphate (dedol-PP) synthase catalyzes cis-

prenyl Prenylation (also known as isoprenylation or lipidation) is the addition of hydrophobic molecules to a protein or a biomolecule. It is usually assumed that prenyl groups (3-methylbut-2-en-1-yl) facilitate attachment to cell membranes, similar ...

chain elongation to produce the polyprenyl backbone of

dolichol Dolichol refers to any of a group of long-chain mostly unsaturated organic compounds that are made up of varying numbers of isoprene units terminating in an α-saturated isoprenoid group, containing an alcohol functional group. Functions Dolicho ...

, a glycosyl carrier lipid required for the biosynthesis of several classes of

glycoprotein Glycoproteins are proteins which contain oligosaccharide chains covalently attached to amino acid side-chains. The carbohydrate is attached to the protein in a cotranslational or posttranslational modification. This process is known as glyco ...

Clinical significance

It has been suggested that

missense mutation In genetics, a missense mutation is a point mutation in which a single nucleotide change results in a codon that codes for a different amino acid. It is a type of nonsynonymous substitution. Substitution of protein from DNA mutations Missense m ...

s in the DHDDS gene are responsible for certain variants of

retinitis pigmentosa Retinitis pigmentosa (RP) is a genetic disorder of the eyes that causes loss of vision. Symptoms include trouble seeing at night and decreasing peripheral vision (side and upper or lower visual field). As peripheral vision worsens, people may ...

. Since it is involved in the early steps of dolichol synthesis, vital ''e.g.'' for correct ''N''-glycosylation, a disease caused by mutations in DHDDS should be considered a

congenital disorder of glycosylation A congenital disorder of glycosylation (previously called carbohydrate-deficient glycoprotein syndrome) is one of several rare inborn errors of metabolism in which glycosylation of a variety of tissue proteins and/or lipids is deficient or defe ...

(and named DHDDS-CDG according to the novel nomenclature of CDGs). Many CDG subtypes present with

as a major feature.

References

External links

GeneReviews/NCBI/NIH/UW entry on Retinitis Pigmentosa Overview
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Function

Clinical significance

References

Further reading

External links