Transmembrane Anterior Posterior Transformation Protein 1 (TAPT1)

TAPT1 encodes a highly conserved, putative transmembrane protein. A mutation in the mouse ortholog of this gene results in homeotic, posterior-to-anterior transformations of the axial skeleton which are similar to the phenotype of mouse homeobox C8 gene mutants. This gene is proposed to function downstream of homeobox C8 to transduce extracellular patterning information during axial skeleton development. An alternatively spliced transcript variant encoding a substantially different isoform has been described, but its biological validity has not been determined.The full-length protein contains 565 amino acids and has as many as 6 transmembrane domains. EST database analysis and RT-PCR analysis confirmed ubiquitous expression of Tapt1 in adult tissues and whole embryos.