APP, Amyloid-beta precursor protein
Also Known as
A4_HUMAN, APP, A4, AD1
Functions as a cell surface receptor and performs physiological functions on the surface of neurons relevant to neurite growth, neuronal adhesion and axonogenesis. Interaction between APP molecules on neighboring cells promotes synaptogenesis (PubMed:25122912). Involved in cell mobility and transcription regulation through protein-protein interactions. Can promote transcription activation through binding to APBB1-KAT5 and inhibits Notch signaling through interaction with Numb. Couples to apoptosis-inducing pathways such as those mediated by G(O) and JIP. Inhibits G(o) alpha ATPase activity (By similarity). Acts as a kinesin I membrane receptor, mediating the axonal transport of beta-secretase and presenilin 1. Involved in copper homeostasis/oxidative stress through copper ion reduction. In vitro, copper-metallated APP induces neuronal death directly or is potentiated through Cu(2+)-mediated low-density lipoprotein oxidation. Can regulate neurite outgrowth through binding to components of the extracellular matrix such as heparin and collagen I and IV. The splice isoforms that contain the BPTI domain possess protease inhibitor activity. Induces a AGER-dependent pathway that involves activation of p38 MAPK, resulting in internalization of amyloid-beta peptide and leading to mitochondrial dysfunction in cultured cortical neurons. Provides Cu(2+) ions for GPC1 which are required for release of nitric oxide (NO) and subsequent degradation of the heparan sulfate chains on GPC1., Amyloid-beta peptides are lipophilic metal chelators with metal-reducing activity. Bind transient metals such as copper, zinc and iron. In vitro, can reduce Cu(2+) and Fe(3+) to Cu(+) and Fe(2+), respectively. Amyloid-beta protein 42 is a more effective reductant than amyloid-beta protein 40. Amyloid-beta peptides bind to lipoproteins and apolipoproteins E and J in the CSF and to HDL particles in plasma, inhibiting metal-catalyzed oxidation of lipoproteins. APP42-beta may activate mononuclear phagocytes in the brain and elicit inflammatory responses. Promotes both tau aggregation and TPK II-mediated phosphorylation. Interaction with overexpressed HADH2 leads to oxidative stress and neurotoxicity. Also binds GPC1 in lipid rafts., Appicans elicit adhesion of neural cells to the extracellular matrix and may regulate neurite outgrowth in the brain., The gamma-CTF peptides as well as the caspase-cleaved peptides, including C31, are potent enhancers of neuronal apoptosis., N-APP binds TNFRSF21 triggering caspase activation and degeneration of both neuronal cell bodies (via caspase-3) and axons (via caspase-6). Binds, via its C-terminus, to the PID domain of several cytoplasmic proteins, including APBB family members, the APBA family, MAPK8IP1, SHC1 and, NUMB and DAB1 (By similarity). Binding to DAB1 inhibits its serine phosphorylation (By similarity). Interacts (via NPXY motif) with DAB2 (via PID domain); the interaction is impaired by tyrosine phosphorylation of the NPXY motif. Also interacts with GPCR-like protein BPP, APPBP1, IB1, KNS2 (via its TPR domains), APPBP2 (via BaSS) and DDB1. In vitro, it binds MAPT via the MT-binding domains (By similarity). Associates with microtubules in the presence of ATP and in a kinesin-dependent manner (By similarity). Interacts, through a C-terminal domain, with GNAO1. Amyloid-beta protein 42 binds CHRNA7 in hippocampal neurons. Amyloid-beta associates with HADH2. Soluble APP binds, via its N-terminal head, to FBLN1. Interacts with CPEB1 and AGER (By similarity). Interacts with ANKS1B and TNFRSF21. Interacts with ITM2B. Interacts with ITM2C. Interacts with IDE. Can form homodimers; dimerization is enhanced in the presence of Cu(2+) ions (PubMed:25122912). Can form homodimers; this is promoted by heparin binding. Amyloid-beta protein 40 interacts with S100A9. CTF-alpha product of APP interacts with GSAP. Interacts with SORL1. Interacts with PLD3. Interacts with VDAC1 (PubMed:25168729). Interacts with NSG1; could regulate APP processing (By similarity). Amyloid-beta protein 42 interacts with FPR2 (PubMed:11689470). Interacts with SYT7 (By similarity). Interacts (via transmembrane region) with PSEN1; the interaction is direct (PubMed:30630874).