Disease relevance of CDON

• Overexpression of the immunoglobulin superfamily members CDO and BOC enhances differentiation of the human rhabdomyosarcoma cell line RD [1].
• Microform holoprosencephaly in mice that lack the Ig superfamily member Cdon [2].
• We investigated the characterization and the regulation of TAUT (taurine transporter) and CDO (cysteine dioxygenase), one of the key enzymes of taurine biosynthesis, in human hepatoblastoma HepG2 cells [3].
• METHODS: In a genome-wide search for PCD loci performed in 52 KS families and in 18 PCD families with no situs inversus present (CDO, ciliary dysfunction-only), the maximal pairwise LOD score of 3.36 with D15S205 in the KS families indicated linkage of a KS locus to the long arm of chromosome 15 [4].

High impact information on CDON

• Other members of the Ihog family, including Drosophila Boi and mammalian CDO and BOC, also interact with Hh ligands via a specific FNIII domain, thus identifying an evolutionarily conserved family of membrane proteins that function in Hh signal response [5].
• Like CDO, BOC accelerates differentiation of cultured myoblast cell lines and participates in a positive feedback loop with the myogenic transcription factor, MyoD [6].
• CDO and BOC are proposed to be components of a receptor complex that mediates some of the cell-cell interactions between muscle precursors that are required for myogenesis [6].
• This is the first example of a mouse mutant with this phenotype, and this finding implicates a new family of receptors in development of the facial midline and suggests a potential role for Cdon in the pathogenesis and expressivity of HPE in humans [2].
• These observations are consistent with the notion that CDO and BOC play a role in the inverse relationship between differentiation and transformation of cells in the skeletal muscle lineage [1].

Biological context of CDON

• Stable expression in myoblasts of a CDO deletion mutant deficient in its ability to associate with N-cadherin interferes with differentiation as assessed by biochemical, morphological, and reporter gene assays, suggesting that this interaction is functionally important in myogenesis [7].
• RESULTS: A maximal pairwise LOD score of 4.34 was observed with D15S154, further supporting linkage of the KS, but not the CDO, families to 15q24-25 [4].

Associations of CDON with chemical compounds

• On the other hand, the expression level of CDO mRNA was not affected under a taurine-rich condition [3].

Other interactions of CDON

• Mutational screening of FGFR1, CER1, and CDON in a large cohort of trigonocephalic patients [8].
• DESIGN: Using single-strand conformational polymorphisms (SSCPs), denaturing high-performance liquid chromatography, and/or direct sequencing, we analyzed a total of 81 patients for FGFR1 (exon 7), 70 for CER1, and 44 for CDON [8].

References