Taxilin contains an extraordinarily long coiled-coil domain in its C-terminal half and is ubiquitously expressed. It is a novel binding partner of several syntaxin family members and is possibly involved in Ca2+-dependent exocytosis in neuroendocrine cells [1]. Gamma-taxilin, described as leucine zipper protein Factor Inhibiting ATF4-mediated Transcription (FIAT), localises to the nucleus in osteoblasts and dimerises with ATF4 to form inactive dimers, thus inhibiting ATF4-mediated transcription [2].

1: Taxilin; a novel syntaxin-binding protein that is involved in Ca2+-dependent exocytosis in neuroendocrine cells. Nogami S, Satoh S, Nakano M, Shimizu H, Fukushima H, Maruyama A, Terano A, Shirataki H; Genes Cells. 2003;8:17-28. PMID:12558796

2: Inhibition of ATF4 transcriptional activity by FIAT/gamma-taxilin modulates bone mass accrual. Yu VW, Gauthier C, St-Arnaud R; Ann N Y Acad Sci. 2006;1068:131-142. PMID:16831913