Positive and negative regulation of the gamma-secretase activity by nicastrin in a murine model.
Nicastrin is a component of the gamma-secretase complex that has been shown to adhere to presenilin-1 (PS1), Notch, and APP. Here we demonstrate that Nicastrin-deficient mice showed a phenotype that is indistinguishable from PS1/PS2 double knock-out mice, whereas heterozygotes were healthy and viable. Fibroblasts derived from Nicastrin-deficient embryos were unable to generate amyloid beta-peptide and failed to release the intracellular domain of APP- or Notch1-Gal4-VP16 fusion proteins. Additionally, C- and N-terminal fragments of PS1 and the C-terminal fragments of PS2 were not detectable in Nicastrin-null fibroblasts, whereas full-length PS1 accumulated in null fibroblasts, indicating that Nicastrin is required for the endoproteolytic processing of presenilins. Interestingly, cells derived from Nicastrin heterozygotes produced relatively higher levels of amyloid beta-peptide whether the source was endogenous mouse or transfected human APP. These data demonstrate that Nicastrin is essential for the gamma-secretase cleavage of APP and Notch in mammalian cells and that Nicastrin has both positive and negative functions in the regulation of gamma-secretase activity.
Li
Jinhe
J
Discovery Research, Pfizer Inc., Kalamazoo, Michigan 49001, USA. jinhe.li@pfizer.com
Fici
Gregory J
GJ
Mao
Chai-An
CA
Myers
Richard L
RL
Shuang
Rongqing
R
Donoho
Gregory P
GP
Pauley
Adele M
AM
Himes
Carol S
CS
Qin
Wenning
W
Kola
Ismail
I
Merchant
Kalpana M
KM
Nye
Jeffrey S
JS
D000256:Adenoviridae / Q000235:genetics; D000483:Alleles; D053829:Amyloid Precursor Protein Secretases; D000818:Animals; D016282:Aspartic Acid Endopeptidases; D002462:Cell Membrane / Q000378:metabolism; D017077:Culture Media, Conditioned / Q000494:pharmacology; D018076:DNA, Complementary / Q000378:metabolism; D010450:Endopeptidases / Q000378:metabolism*; D005347:Fibroblasts / Q000378:metabolism; D015971:Gene Expression Regulation, Enzymologic; D017930:Genes, Reporter; D005838:Genotype; D049452:Green Fluorescent Proteins; D006579:Heterozygote; D006801:Humans; D008156:Luciferases / Q000378:metabolism; D008164:Luminescent Proteins / Q000378:metabolism; D008562:Membrane Glycoproteins / Q000235:genetics* / Q000378:metabolism* / Q000502:physiology; D008565:Membrane Proteins / Q000502:physiology; D051379:Mice; D018345:Mice, Knockout; D010455:Peptides / Q000737:chemistry; D010641:Phenotype; D053764:Presenilin-1; D053766:Presenilin-2; D017434:Protein Structure, Tertiary; D012333:RNA, Messenger / Q000378:metabolism; D011993:Recombinant Fusion Proteins / Q000737:chemistry / Q000378:metabolism; D013997:Time Factors
D017077:Culture Media, Conditioned; D018076:DNA, Complementary; D008164:Luminescent Proteins; D008562:Membrane Glycoproteins; D008565:Membrane Proteins; C508853:PSEN1 protein, human; C508861:PSEN2 protein, human; D010455:Peptides; D053764:Presenilin-1; D053766:Presenilin-2; D012333:RNA, Messenger; D011993:Recombinant Fusion Proteins; C413604:nicastrin protein; D049452:Green Fluorescent Proteins; D008156:Luciferases; D053829:Amyloid Precursor Protein Secretases; D010450:Endopeptidases; D016282:Aspartic Acid Endopeptidases; C509280:BACE1 protein, human; C509282:Bace1 protein, mouse