The SRY and SOX proteins share a DNA-binding domain known as the HMG box, defined by a 79-amino acid
region. All SOX proteins have a single HMG box and bind linear DNA in a sequence-specific manner, resulting in the bending
of DNA through large angles. Bending causes the DNA helix to open for some distance, which may affect binding and
interactions of other transcription factors.
General function
Nucleic acid binding, DNA binding, Transcription factor
Comment
Cellular localization
Nuclear
Comment
Ovarian function
Comment
Yamashita A, et al 1998 reported cDNA cloning of a novel rainbow trout SRY-type HMG box
protein, rtSox23, and its functional analysis.
They have isolated a cDNA clone for a new member of Sox genes, termed rtSox23,
from a rainbow trout ovary cDNA library. rtSox23 mRNA was notably expressed in
ovary and brain. rtSox23 contains a leucine zipper in addition to an SRY-type HMG
box. Although the recombinant HMG box region protein of rtSox23 could bind to an
AACAAT sequence, the full-length rtSox23 could form a homodimer and did not bind
to the sequence. Furthermore, using a two-hybrid system, they have isolated a cDNA
clone encoding a protein that bound to the leucine zipper region of rtSox23. This
protein was the rainbow trout homologue of mouse nucleoporin p62, which is a
component of the nuclear pore complex in nuclear envelope. The rainbow trout p62
mRNA was also prominent in ovary and brain. Taken together, these results suggest
that the rainbow trout p62 associates with rtSox23 in vivo and modulates the function
of rtSox23.