ATL1 and hereditary spastic paraplegia: Indeed, HSP-causing mutations were shown to disrupt BMP receptors II trafficking to the cell surface in HEK239-T cells [61] and knockdown of zebrafish atl1 decreases larval mobility, perturbs the architecture of spinal motor axons and is associated with a substantial upregulation of the BMP signaling pathway, again implying that atlastins may regulate BMP receptor trafficking [62].