ARF GTPase-activating protein GIT2 is an
enzyme
Enzymes () are proteins that act as biological catalysts by accelerating chemical reactions. The molecules upon which enzymes may act are called substrate (chemistry), substrates, and the enzyme converts the substrates into different molecule ...
that in humans is encoded by the ''GIT2''
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
This gene encodes a member of the GIT protein family. GIT proteins interact with G protein-coupled receptor kinases and possess ADP-ribosylation factor (ARF) GTPase-activating protein (GAP) activity. This gene undergoes extensive alternative splicing; although ten transcript variants have been described, the full length sequence has been determined for only four variants. The various isoforms have functional differences, with respect to ARF GAP activity and to G protein-coupled receptor kinase 2 binding.
Model organisms
Model organisms have been used in the study of GIT2 function. A conditional
knockout mouse
A knockout mouse, or knock-out mouse, is a genetically modified mouse (''Mus musculus'') in which researchers have inactivated, or " knocked out", an existing gene by replacing it or disrupting it with an artificial piece of DNA. They are importa ...
line, called ''Git2
Gt(XG510)Byg''
was generated as part of the
International Knockout Mouse Consortium
The International Knockout Mouse Consortium (IKMC) is a scientific endeavour to produce a collection of mouse embryonic stem cell lines that together lack every gene in the genome, and then to distribute the cells to scientific researchers to cr ...
program — a high-throughput mutagenesis project to generate and distribute animal models of disease to interested scientists — at the
Wellcome Trust Sanger Institute
The Wellcome Sanger Institute, previously known as The Sanger Centre and Wellcome Trust Sanger Institute, is a non-profit British genomics and genetics research institute, primarily funded by the Wellcome Trust.
It is located on the Wellcome Ge ...
.
Male and female animals underwent a standardized
phenotypic screen
In genetics, the phenotype () is the set of observable characteristics or traits of an organism. The term covers the organism's morphology or physical form and structure, its developmental processes, its biochemical and physiological prop ...
to determine the effects of deletion.
Mice lacking ''Git2'' had no significant defects in viability or
fertility
Fertility is the capability to produce offspring through reproduction following the onset of sexual maturity. The fertility rate is the average number of children born by a female during her lifetime and is quantified demographically. Ferti ...
,
so further tests were carried out and four significant
phenotypes
In genetics, the phenotype () is the set of observable characteristics or traits of an organism. The term covers the organism's morphology or physical form and structure, its developmental processes, its biochemical and physiological prop ...
were reported:
*
Mutant
In biology, and especially in genetics, a mutant is an organism or a new genetic character arising or resulting from an instance of mutation, which is generally an alteration of the DNA sequence of the genome or chromosome of an organism. It ...
mice had differences in their
clinical blood chemistry compared to
wildtype
The wild type (WT) is the phenotype of the typical form of a species as it occurs in nature. Originally, the wild type was conceptualized as a product of the standard "normal" allele at a locus, in contrast to that produced by a non-standard, "m ...
control mice.
* Mutant male mice had a decrease in
white blood cell count.
* An increased thickness in
hippocampus
The hippocampus (via Latin from Greek , ' seahorse') is a major component of the brain of humans and other vertebrates. Humans and other mammals have two hippocampi, one in each side of the brain. The hippocampus is part of the limbic system, ...
was observed.
* Mutant female mice were slower to respond to heat when placed on a
hotplate.
Interactions
GIT2 has been shown to
interact with
GIT1
ARF GTPase-activating protein GIT1 is an enzyme that in humans is encoded by the ''GIT1'' gene.
GIT1 contains an ARFGAP domain, Anykrin repeats, and a GRK-interacting domain. The Arf-GAP domain, which enables it to act as a GTPase activating prot ...
.
References
Further reading
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{{refend
Genes mutated in mice