Sphingolipid activator proteins (SAPs) in neuronal ceroid lipofuscinoses (NCL)

Based on the predominant component of the storage material the neuronal ceroid lipofuscinoses (NCL) can be divided into two categories: one storing mitochondrial ATP synthase subunit c and the other storing sphingolipid activator proteins (SAPs). The latter group is represented by the human infantile NCL (INCL), a congenital ovine NCL, and a canine NCL. Small amounts of SAPs also accumulate in most other forms of NCL. The SAPs, their functions and occurrence in different forms of NCL, as well as the relationship between SAPs and palmitoyl protein thioesterase, an enzyme implicated in INCL, are discussed.