Rab escort protein 1 (REP1) also known as rab proteins geranylgeranyltransferase component A 1 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. A ...
that in humans is encoded by the ''CHM''
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
This gene encodes component A of the
RAB geranylgeranyl transferase holoenzyme. In the dimeric holoenzyme, this subunit binds unprenylated Rab GTPases and then presents them to the catalytic Rab GGTase subunit for the geranylgeranyl transfer reaction. Rab GTPases need to be on either one or two
cysteine
Cysteine (symbol Cys or C; ) is a semiessential proteinogenic amino acid with the formula . The thiol side chain in cysteine often participates in enzymatic reactions as a nucleophile.
When present as a deprotonated catalytic residue, sometime ...
residues in their
C-terminus
The C-terminus (also known as the carboxyl-terminus, carboxy-terminus, C-terminal tail, C-terminal end, or COOH-terminus) is the end of an amino acid chain (protein or polypeptide), terminated by a free carboxyl group (-COOH). When the protein is ...
to localize to the correct intracellular membrane.
Interactions
CHM (gene) has been shown to
interact
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with
RAB1A
Ras-related protein Rab-1A is a protein that in humans is encoded by the ''RAB1A'' gene.
Interactions
RAB1A has been shown to interact
Advocates for Informed Choice, doing business as, dba interACT or interACT Advocates for Intersex Youth ...
,
RAB7A
Ras-related protein Rab-7a is a protein that in humans is encoded by the ''RAB7A'' gene.
Ras-related protein Rab-7a is involved in endocytosis, which is a process that brings substances into a cell. The process of endocytosis works by folding the ...
and
RAB3A
Ras-related protein Rab-3A is a protein that in humans is encoded by the ''RAB3A'' gene. It is involved in calcium-triggered exocytosis in neurons.
Interactions
RAB3A has been shown to interact with:
* RIMS1,
*UNC13A
Unc-13 homolog A (''C. ...
.
Clinical significance
Mutations in this gene are a cause of choroideremia
Choroideremia (; CHM) is a rare, X-linked recessive form of hereditary retinal degeneration that affects roughly 1 in 50,000 males. The disease causes a gradual loss of vision, starting with childhood night blindness, followed by peripheral vision ...
; also known as tapetochoroidal dystrophy (TCD). This X-linked disease is characterized by progressive dystrophy of the choroid, retinal pigment epithelium and retina.
See also
* Rab (G-protein)
The Rab family of proteins is a member of the Ras superfamily of small G proteins. Approximately 70 types of Rabs have now been identified in humans. Rab proteins generally possess a GTPase fold, which consists of a six-stranded beta sheet which is ...
References
Further reading
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External links
GeneReviews/NCBI/NIH/UW entry on Choroideremia
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