Phospho-TTF-1 (Ser327) Antibody #13608

Thyroid Transcription Factor 1 (TTF-1, also known as NKX2-1), a member of the NKX homeobox transcription factor family, was initially discovered in the FRTL-5 rat thyroid cell line (1). Subsequent studies have shown that TTF-1 plays an important role in differentiation and morphogenesis of the developing thyroid, lung, and ventral forebrain (2). TTF-1 controls the expression of several genes, some of which are tissue specific, such as: thyroglobulin, thyroperoxidase, and the thyrotropin receptor in the thyroid; and surfactant proteins and clara cell secretory protein in the lung (2,3). Investigators have found that TTF-1 is expressed in malignant tumors of the thyroid and lung, and it is commonly used as a marker for both primary and malignant lung cancers (4-6).
Research studies have shown that activation of the Raf/MEK/ERK signaling pathway results in phosphorylation of TTF-1 at multiple residues, including Ser18, Ser327, and Ser337 (7). Concomitant phosphorylation at these residues was shown to suppress the transcriptional activity of TTF-1 in a rat follicular thyroid cell model (7). These findings are consistent with previous studies demonstrating a reduction in thyroid-specific gene expression in Ras-transformed thyroid cells (8,9).