Rho GTPase activating protein 26 (ARHGAP26) also known as GTPase Regulator Associated with Focal Adhesion Kinase (GRAF) is a

protein Proteins are large biomolecules and macromolecules that comprise one or more long chains of amino acid residue (biochemistry), residues. Proteins perform a vast array of functions within organisms, including Enzyme catalysis, catalysing metab ...

that in humans is encoded by the ''ARHGAP26''

gene In biology, the word gene has two meanings. The Mendelian gene is a basic unit of heredity. The molecular gene is a sequence of nucleotides in DNA that is transcribed to produce a functional RNA. There are two types of molecular genes: protei ...

Function

GRAF1 is a multidomain protein that is necessary for the CLIC/ GEEC endocytic pathway. By virtue of an N-terminal

BAR domain In molecular biology, BAR domains are highly conserved protein dimerisation domains that occur in many proteins involved in membrane dynamics in a cell. The BAR domain is banana-shaped and binds to membrane via its concave face. It is cap ...

, GRAF1 sculpts the endocytic membranes of this pathway into 40 nm diameter tubules and vesicles that allow uptake of extracellular fluid, GPI-linked proteins and certain bacterial exotoxins into cells. The role of

dynamin Dynamin is a GTPase protein responsible for endocytosis in the eukaryotic cell. Dynamin is part of the "dynamin superfamily", which includes classical dynamins, dynamin-like proteins, MX1, Mx proteins, OPA1, MFN1, mitofusins, and Guanylate-bindin ...

in the CLIC/GEEC pathway is controversial, but GRAF1 interacts strongly with this protein and acute inhibition of

action abrogates CLIC/GEEC

endocytosis Endocytosis is a cellular process in which Chemical substance, substances are brought into the cell. The material to be internalized is surrounded by an area of cell membrane, which then buds off inside the cell to form a Vesicle (biology and chem ...

. There are several members of the GRAF family of proteins, including GRAF2, GRAF3, and oligophrenin, all of which likely playing similar roles during clathrin-independent endocytic events. Mutations of both GRAF1 and oligophrenin are strongly implicated in causing human disease (

leukaemia Leukemia ( also spelled leukaemia; pronounced ) is a group of blood cancers that usually begin in the bone marrow and produce high numbers of abnormal blood cells. These blood cells are not fully developed and are called ''blasts'' or '' ...

and

mental retardation Intellectual disability (ID), also known as general learning disability (in the United Kingdom), and formerly mental retardation (in the United States), Rosa's Law, Pub. L. 111-256124 Stat. 2643(2010).Archive is a generalized neurodevelopmental ...

, respectively). Recently,

autoantibodies An autoantibody is an antibody (a type of protein) produced by the immune system that is directed against one or more of the individual's own proteins. Many autoimmune diseases (notably lupus erythematosus) are associated with such antibodies. Pr ...

to ARHGAP26 have been implicated in autoimmune

cerebellar ataxia Cerebellar ataxia is a form of ataxia originating in the cerebellum. Non-progressive congenital ataxia (NPCA) is a classical presentation of cerebral ataxias. Cerebellar ataxia can occur as a result of many diseases and may present with symptoms ...

Function

Interactions

References

Further reading

External links