title: A CBP binding transcriptional repressor produced by the PS1/epsilon-cleavage of N-cadherin is inhibited by PS1 FAD mutations.
abstract: Presenilin1 (PS1), a protein implicated in Alzheimer's disease (AD), forms complexes with N-cadherin, a transmembrane protein with important neuronal and synaptic functions. Here, we show that a PS1-dependent gamma-secretase protease activity promotes an epsilon-like cleavage of N-cadherin to produce its intracellular domain peptide, N-Cad/CTF2. NMDA receptor agonists stimulate N-Cad/CTF2 production suggesting that this receptor regulates the epsilon-cleavage of N-cadherin. N-Cad/CTF2 binds the transcription factor CBP and promotes its proteasomal degradation, inhibiting CRE-dependent transactivation. Thus, the PS1-dependent epsilon-cleavage product N-Cad/CTF2 functions as a potent repressor of CBP/CREB-mediated transcription. Importantly, PS1 mutations associated with familial AD (FAD) and a gamma-secretase dominant-negative mutation inhibit N-Cad/CTF2 production and upregulate CREB-mediated transcription indicating that FAD mutations cause a gain of transcriptional function by inhibiting production of transcriptional repressor N-Cad/CTF2. These data raise the possibility that FAD mutation-induced transcriptional abnormalities maybe causally related to the dementia associated with FAD.
mesh_terms: D053829:Amyloid Precursor Protein Secretases; D000818:Animals; D016282:Aspartic Acid Endopeptidases; D015153:Blotting, Western; D015820:Cadherins / Q000737:chemistry / Q000378:metabolism*; D002352:Carrier Proteins / Q000378:metabolism*; D002460:Cell Line; D002462:Cell Membrane / Q000378:metabolism; D002478:Cells, Cultured; D003546:Cysteine Endopeptidases / Q000378:metabolism; D003593:Cytoplasm / Q000378:metabolism; D004305:Dose-Response Relationship, Drug; D015536:Down-Regulation; D010450:Endopeptidases / Q000378:metabolism; D005799:Genes, Dominant; D005822:Genetic Vectors; D006801:Humans; D015151:Immunoblotting; D008565:Membrane Proteins / Q000378:metabolism; D051379:Mice; D008856:Microscopy, Fluorescence; D009097:Multienzyme Complexes / Q000378:metabolism; D009154:Mutation; D009474:Neurons / Q000378:metabolism; D010455:Peptides / Q000737:chemistry; D011233:Precipitin Tests; D053764:Presenilin-1; D046988:Proteasome Endopeptidase Complex; D011485:Protein Binding; D017434:Protein Structure, Tertiary; D020133:Reverse Transcriptase Polymerase Chain Reaction; D013347:Subcellular Fractions / Q000378:metabolism; D013569:Synapses / Q000378:metabolism; D013997:Time Factors; D014158:Transcription, Genetic; D015533:Transcriptional Activation; D014404:Tubulin / Q000378:metabolism
chemical_list: D015820:Cadherins; D002352:Carrier Proteins; D008565:Membrane Proteins; D009097:Multienzyme Complexes; C508853:PSEN1 protein, human; D010455:Peptides; D053764:Presenilin-1; D014404:Tubulin; C020723:citrate-binding transport protein; D053829:Amyloid Precursor Protein Secretases; D010450:Endopeptidases; D003546:Cysteine Endopeptidases; D016282:Aspartic Acid Endopeptidases; C509280:BACE1 protein, human; C509282:Bace1 protein, mouse; D046988:Proteasome Endopeptidase Complex