TY - JOUR
T1 - PEN-2 and APH-1 coordinately regulate proteolytic processing of presenilin 1
AU - Luo, Wen jie
AU - Wang, Hong
AU - Li, Hongqiao
AU - Kim, Benny S.
AU - Shah, Sanjiv
AU - Lee, Hahn Jun
AU - Thinakaran, Gopal
AU - Kim, Tae Wan
AU - Yu, Gang
AU - Xu, Huaxi
PY - 2003/3/7
Y1 - 2003/3/7
N2 - Presenilin (PS, PS1/PS2) complexes are known to be responsible for the intramembranous γ-secretase cleavage of the β-amyloid precursor protein and signaling receptor Notch. PS holoprotein undergoes endoproteolysis by an unknown enzymatic activity to generate NH2- and COOH-terminal fragments, a process that is required for the formation of the active and stable PS/-γ-secretase complex. Biochemical and genetic studies have recently identified nicastrin, APH-1, and PEN-2 as essential cofactors that physically interact with PS1 and are necessary for the γ-secretase activity. However, their precise function in regulating the PS complex and γ-secretase activity remains unknown. Here, we demonstrate that endogenous PEN-2 preferentially interacts with PS1 holoprotein. Down-regulation of PEN-2 expression by small interfering RNA (siRNA) abolishes the endoproteolysis of PS1, whereas overexpression of PEN-2 promotes the production of PS1 fragments, indicating a critical role for PEN-2 in PS1 endoproteolysis. Interestingly, accumulation of full-length PS1 resulting from down-regulation of PEN-2 is alleviated by additional siRNA down-regulation of APH-1. Furthermore, overexpression of APH-1 facilitates PEN-2-mediated PS1 proteolysis, resulting in a significant increase in PS1 fragments. Our data reveal a direct role of PEN-2 in proteolytic cleavage of PS1 and a regulatory function of APH-1, in coordination with PEN-2, in the biogenesis of the PS1 complex.
AB - Presenilin (PS, PS1/PS2) complexes are known to be responsible for the intramembranous γ-secretase cleavage of the β-amyloid precursor protein and signaling receptor Notch. PS holoprotein undergoes endoproteolysis by an unknown enzymatic activity to generate NH2- and COOH-terminal fragments, a process that is required for the formation of the active and stable PS/-γ-secretase complex. Biochemical and genetic studies have recently identified nicastrin, APH-1, and PEN-2 as essential cofactors that physically interact with PS1 and are necessary for the γ-secretase activity. However, their precise function in regulating the PS complex and γ-secretase activity remains unknown. Here, we demonstrate that endogenous PEN-2 preferentially interacts with PS1 holoprotein. Down-regulation of PEN-2 expression by small interfering RNA (siRNA) abolishes the endoproteolysis of PS1, whereas overexpression of PEN-2 promotes the production of PS1 fragments, indicating a critical role for PEN-2 in PS1 endoproteolysis. Interestingly, accumulation of full-length PS1 resulting from down-regulation of PEN-2 is alleviated by additional siRNA down-regulation of APH-1. Furthermore, overexpression of APH-1 facilitates PEN-2-mediated PS1 proteolysis, resulting in a significant increase in PS1 fragments. Our data reveal a direct role of PEN-2 in proteolytic cleavage of PS1 and a regulatory function of APH-1, in coordination with PEN-2, in the biogenesis of the PS1 complex.
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U2 - 10.1074/jbc.C200648200
DO - 10.1074/jbc.C200648200
M3 - Article
C2 - 12522139
AN - SCOPUS:0037424275
SN - 0021-9258
VL - 278
SP - 7850
EP - 7854
JO - Journal of Biological Chemistry
JF - Journal of Biological Chemistry
IS - 10
ER -