SCFD1 is a 642 amino acid protein that belongs to the STXBP/unc-18/SEC1 family. Phosphorylated upon DNA damage, probably by Atm or ATR, SCFD1 is involved in vesicular transport between the endoplasmic reticulum (ER) and the Golgi. The SCFD1 protein plays a role in SNARE-pin assembly and Golgi to ER retrograde transport via its interaction with COG4. The SCFD1 protein also binds Syntaxin 5. The SCFD1 gene is conserved in chimpanzee, dog, cow, mouse, rat, chicken, zebrafish, mosquito, Drosophila, C.elegans, S.pombe, S.cerevisiae, K.lactis, E.gossypii, M.grisea, N.crassa, A.thaliana and rice, and maps to human chromosome 14q12. Deletion of a region of chromosome 14 that contains BF-1, PKC ? SCFD1, Cochlin and SG2NA genes, is responsible for a condition resulting in severe mental retardation, epilepsy, microcephaly and Rett-like features.