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General Comment |
The SRY (OMIM 480000) 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. Katoh M. 2002 reported the molecular cloning and characterization of human SOX17.
SOX proteins are a family of transcription factors with high-mobility-group
DNA-binding domain (HMG box) homologous to SRY, which are implicated in
embryogenesis. Xenopus Sox17alpha, Sox17beta, and Sox3 are reported to negatively
modulate the WNT - beta-catenin - TCF signaling pathway. Here, human SOX17 gene
fragments were identified in human genome draft sequences by using bioinformatics,
and SOX17 cDNAs were isolated by using cDNA-PCR. Human SOX17 was found to
encode a 414-amino-acid protein with a HMG box, which was homologous to SOX18
and SOX7. SOX17 gene, consisting of 2 exons, was located in human chromosome
8q12-q13 region. SOX17 mRNAs of 2.5- and 2.2-kb in size were detected in adult
heart, lung, spleen, testis, ovary, placenta, fetal lung, and kidney. In normal
gastrointestinal tract, SOX17 mRNA was preferentially expressed in esophagus,
stomach and small intestine than in colon and rectum. SOX17 mRNA was almost
undetectable in human cancer cell lines HL-60, HeLa S3, K-562, MOLT-4, Raji,
SW480, A549, G-361, and also in 66 cases of human primary tumors derived from
various tissues, except one case of primary cervical cancer. This is the first report on
molecular cloning and characterization of human SOX17.
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