Reconstitution of gamma-secretase by truncated presenilin (PS) fragments revealed that PS C-terminal transmembrane domain is critical for formation of gamma-secretase complex.
The presenilin (PS) complex, including PS, nicastrin (NCT), APH-1 and PEN-2, is essential for gamma-secretase activity. Previously, the PS C-terminal tail was shown to be essential for gamma-secretase activity. Here, to further understand the precise mechanism underlying the activation of gamma-secretase regulated by PS cofactors, we focused on the role of the PS1 C-terminal region including transmembrane domain (TM) 8 in gamma-secretase activity. For this purpose, we co-expressed C-terminally truncated PS1 (PS1DeltaC) completely lacking gamma-secretase activity and the PS1 C-terminal short fragment in PS-null cells, because the successful reconstitution of gamma-secretase activity in PS-null cells by the co-expression of PS1DeltaC and the PS1 C-terminal short fragment would allow us to investigate the role of the PS1 C-terminal region in gamma-secretase activity. We found that the exogenous expression of the PS1 C-terminal short fragment with NCT and APH-1 completely rescued a defect of the gamma-secretase activity of PS1DeltaC in PS-null cells. With this reconstitution system, we demonstrate that both TM8 and the PS1 C-terminal seven-amino-acid-residue tail are involved in the formation of the active gamma-secretase complex via the assembly of PS1 with NCT and APH-1.
Shiraishi
Hirohisa
H
Department of Alzheimer's Disease Research, National Institute for Longevity Sciences, 36-3 Gengo, Obu, Aichi 474-8522, Japan.
Marutani
Toshihiro
T
Wang
Hua-Qin
HQ
Maeda
Yasuhiro
Y
Kurono
Yukihisa
Y
Takashima
Akihiko
A
Araki
Wataru
W
Nishimura
Masaki
M
Yanagisawa
Katsuhiko
K
Komano
Hiroto
H
D053829:Amyloid Precursor Protein Secretases; D016282:Aspartic Acid Endopeptidases; D010450:Endopeptidases / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism*; D017353:Gene Deletion; D006801:Humans; D008565:Membrane Proteins / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism / Q000494:pharmacology; D010446:Peptide Fragments / Q000235:genetics* / Q000378:metabolism / Q000494:pharmacology; D053764:Presenilin-1; D017434:Protein Structure, Tertiary
D008565:Membrane Proteins; C508853:PSEN1 protein, human; D010446:Peptide Fragments; D053764:Presenilin-1; D053829:Amyloid Precursor Protein Secretases; D010450:Endopeptidases; D016282:Aspartic Acid Endopeptidases; C509280:BACE1 protein, human