Thyroid Cancer Protein 1 (TC1)

C8orf4 encodes a small, monomeric, predominantly unstructured protein that functions as a positive regulator of the Wnt/beta-catenin signaling pathway. This protein interacts with a repressor of beta-catenin mediated transcription at nuclear speckles. It is thought to competitively block interactions of the repressor with beta-catenin, resulting in up-regulation of beta-catenin target genes. By 5-prime RACE and primer extension analysis, they obtained the full-length TC1 cDNA, which encodes a deduced 106-amino acid protein with a calculated molecular mass of about 12 kD. Northern blot analysis detected a 1.4-kb transcript in several thyroid cancers. RNA dot blot analysis revealed expression in all tissues examined, with relatively lower levels in brain, thymus, and leukocytes.