This 14 amino acid motif has been identified within the C-terminal region of
several Paired-like homeodomain (HD) (see <PDOC00027>) containing proteins [1,2]. It was named OAR domain after the initials of otp, aristaless, and rax
Although it has been proposed that this domain could be important for
transactivation and be involved in protein-protein interactions or DNA binding
[3,4], its function is not yet known.
Some proteins known to contain an OAR domain are listed below:
Human RIEG. Defects in this protein are the cause of Rieger syndrome, an
autosomal dominant disorder that includes anomalies of the anterior chamber
of the eye, dental hypoplasia and a protuberant umbilicus .
Mammalian OG12X. The function of these proteins is not yet known .
Vertebrate Rax, encoded by the retina and anterior neural fold homeobox
gene. This protein plays a role in the proliferation and/or differentiation
of retinal cell .
Drosophila DRX. It could be a homolog of vertebrate Rax. It appears to be
important in brain development .
Human SHOX, encoded by the short stature homeobox-containing gene. Defects
or lack of this protein are the cause of short stature associated with the
Turner syndrome .
Mammalian PITX3. This protein appears to be involved in normal eye
anterior-chamber and lens development [6,7]. In human, defects in PITX3 are
associated with anterior segment mesenchymal dysgenesis (ASMD) and
autosomal-dominant congenital cataracts (ADCC) .
Vertebrate Pax3 and Pax7, transcription factors that play fundamental roles
in the development of multi-cellular animals (Metazoa) .
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