Nicastrin and presenilin are two major components of the gamma-secretase complex, which executes the intramembrane proteolysis of type I integral membrane proteins such as the amyloid precursor protein (APP) and Notch. Nicastrin is synthesised in fibroblasts and neurons as an endoglycosidase-H-sensitive glycosylated precursor protein (immature nicastrin) and is then modified by complex glycosylation in the Golgi apparatus and by sialylation in the trans-Golgi network (mature nicastrin) [1]. A region featured in this family has a fold similar to human transferrin receptor (TfR, Swiss:P02786) and a bacterial aminopeptidase (Swiss:P80561). It is implicated in the pathogenesis of Alzheimer's disease [4].

1: gamma-Secretase activity requires the presenilin-dependent trafficking of nicastrin through the Golgi apparatus but not its complex glycosylation. Herreman A, Van Gassen G, Bentahir M, Nyabi O, Craessaerts K, Mueller U, Annaert W, De Strooper B; J Cell Sci 2003;116:1127-1136. PMID:12584255

2: Nicastrin is a resident lysosomal membrane protein. Bagshaw RD, Pasternak SH, Mahuran DJ, Callahan JW; Biochem Biophys Res Commun 2003;300:615-618. PMID:12507492

3: Nicastrin modulates presenilin-mediated notch/glp-1 signal transduction and betaAPP processing. Yu G, Nishimura M, Arawaka S, Levitan D, Zhang L, Tandon A, Song YQ, Rogaeva E, Chen F, Kawarai T, Supala A, Levesque L, Yu H, Yang DS, Holmes E, Milman P, Liang Y, Zhang DM, Xu DH, Sato C, Rogaev E, Smith M, Janus C, Zhang Y, Aebersold R, Farrer LS, Sorb Nature 2000;407:48-54. PMID:10993067

4: Nicastrin, a presenilin-interacting protein, contains an aminopeptidase/transferrin receptor superfamily domain. Fagan R, Swindells M, Overington J, Weir M; Trends Biochem Sci 2001;26:213-214. PMID:11295540