| Abstrakt: |
Background:Thyroid hormone is prerequisite for proper fetal and postnatal neurodevelopment, growth, and metabolism. Although much progress has been made in the characterization of genes implicated in thyroid development and function, the majority of genes involved in this process are still unknown. We have previously applied serial analysis of gene expression (SAGE) to identify novel genes preferentially expressed in the thyroid, and this has resulted in the characterization of DUOX2and IYD(also known as DEHAL1), two genes encoding essential enzymes in the production of thyroid hormone. In the current study we characterize the gene C16orf89, which is linked to another thyroid-specific SAGE tag CCAGCTGCCT.Methods:We establish tissue-specific expression of C16orf89using novel tissue-specific SAGE libraries and quantitative polymerase chain reaction. In addition, we characterize the C16orf89gene and protein, and analyze its mRNA expression in response to thyrotropin and during mouse development.Results:C16orf89is predominantly expressed in human thyroid tissue with a specificity intermediate between thyroid transcription factors and proteins involved in thyroid hormone synthesis. C16orf89shows the same expression pattern as Nkx2-1(thyroid transcription factor 1) from embryonic day (E) 17.5 onward in the developing mouse thyroid and lung. The developmental timing of C16orf89mRNA expression is similar to that of the iodide transporter Slc5a5(also known as Nis). Both transcripts are detected from E17.5 in the developing thyroid. This is clearly later than the onset of TgmRNA expression (from E14.5), while Nkx2-1and IydmRNA can already be detected in the E12.5 thyroid. In in vitrocell culture C16orf89expression is stimulated by thyrotropin. The major splice variant encodes a 361 amino acid protein that is well conserved between mammals, contains an N-terminal signal peptide, is secreted in a glycosylated form, and does not contain any known functional domain.Conclusions:We present a novel gene highly expressed in thyroid that encodes a currently enigmatic protein. [ABSTRACT FROM AUTHOR] |
