gamma-Secretase substrate selectivity can be modulated directly via interaction with a nucleotide-binding site.
gamma-Secretase is an unusual protease with an intramembrane catalytic site that cleaves many type I membrane proteins, including the amyloid beta-protein (Abeta) precursor (APP) and the Notch receptor. Genetic and biochemical studies have identified four membrane proteins as components of gamma-secretase: heterodimeric presenilin composed of its N- and C-terminal fragments, nicastrin, Aph-1, and Pen-2. Here we demonstrated that certain compounds, including protein kinase inhibitors and their derivatives, act directly on purified gamma-secretase to selectively block cleavage of APP- but not Notch-based substrates. Moreover, ATP activated the generation of the APP intracellular domain and Abeta, but not the generation of the Notch intracellular domain by the purified protease complex, and was a direct competitor of the APP-selective inhibitors, as were other nucleotides. In accord, purified gamma-secretase bound specifically to an ATP-linked resin. Finally, a photoactivable ATP analog specifically labeled presenilin 1-C-terminal fragments in purified gamma-secretase preparations; the labeling was blocked by ATP itself and APP-selective gamma-secretase inhibitors. We concluded that a nucleotide-binding site exists within gamma-secretase, and certain compounds that bind to this site can specifically modulate the generation of Abeta while sparing Notch. Drugs targeting the gamma-secretase nucleotide-binding site represent an attractive strategy for safely treating Alzheimer disease.
Fraering
Patrick C
PC
Center for Neurologic Diseases, Brigham & Women's Hospital and Harvard Medical School, Boston, Massachusetts 02115, USA.
Ye
Wenjuan
W
LaVoie
Matthew J
MJ
Ostaszewski
Beth L
BL
Selkoe
Dennis J
DJ
Wolfe
Michael S
MS
D000255:Adenosine Triphosphate / Q000378:metabolism*; D053829:Amyloid Precursor Protein Secretases; D000818:Animals; D016282:Aspartic Acid Endopeptidases; D001549:Benzamides; D016466:CHO Cells; D006224:Cricetinae; D010450:Endopeptidases / Q000378:metabolism*; D004791:Enzyme Inhibitors / Q000494:pharmacology; D006367:HeLa Cells; D006801:Humans; D006868:Hydrolysis; D000068877:Imatinib Mesylate; D019920:Photoaffinity Labels; D010879:Piperazines / Q000494:pharmacology; D011743:Pyrimidines / Q000494:pharmacology; D051880:Receptors, Notch / Q000378:metabolism; D013379:Substrate Specificity
D001549:Benzamides; D004791:Enzyme Inhibitors; D019920:Photoaffinity Labels; D010879:Piperazines; D011743:Pyrimidines; D051880:Receptors, Notch; D000068877:Imatinib Mesylate; D000255:Adenosine Triphosphate; D053829:Amyloid Precursor Protein Secretases; D010450:Endopeptidases; D016282:Aspartic Acid Endopeptidases; C509280:BACE1 protein, human