2li9
From Proteopedia
Metal binding domain of rat beta-amyloid
Structural highlights
FunctionA4_RAT Functions as a cell surface receptor and performs physiological functions on the surface of neurons relevant to neurite growth, neuronal adhesion and axonogenesis. Involved in cell mobility and transcription regulation through protein-protein interactions (By similarity). Can promote transcription activation through binding to APBB1-KAT5 and inhibit Notch signaling through interaction with Numb (By similarity). Couples to apoptosis-inducing pathways such as those mediated by G(O) and JIP. Inhibits G(o) alpha ATPase activity. Acts as a kinesin I membrane receptor, mediating the axonal transport of beta-secretase and presenilin 1 (By similarity). May be involved in copper homeostasis/oxidative stress through copper ion reduction. Can regulate neurite outgrowth through binding to components of the extracellular matrix such as heparin and collagen I and IV (By similarity). 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 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 (By similarity). Beta-amyloid peptides are lipophilic metal chelators with metal-reducing activity. Binds transient metals such as copper, zinc and iron. Rat and mouse beta-amyloid peptides bind only weakly transient metals and have little reducing activity due to substitutions of transient metal chelating residues. Beta-APP42 may activate mononuclear phagocytes in the brain and elicits inflammatory responses. Promotes both tau aggregation and TPK II-mediated phosphorylation. Also bind GPC1 in lipid rafts (By similarity). 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 (By similarity). N-APP binds TNFRSF21 triggering caspase activation and degeneration of both neuronal cell bodies (via caspase-3) and axons (via caspase-6) (By similarity). Publication Abstract from PubMedIn an attempt to reveal the mechanism of rats' resistance to Alzheimer's disease, we determined the structure of the metal-binding domain 1-16 of rat beta-amyloid (rat Abeta(1-16)) in solution in the absence and presence of zinc ions. A zinc-induced dimerization of the domain was detected. The zinc coordination site was found to involve residues His-6 and His-14 of both peptide chains. We used experimental restraints obtained from analyses of NMR and isothermal titration calorimetry data to perform structure calculations. The calculations employed an explicit water environment and a simulated annealing molecular-dynamics protocol followed by quantum-mechanical/molecular-mechanical optimization. We found that the C-tails of the two polypeptide chains of the rat Abeta(1-16) dimer are oriented in opposite directions to each other, which hinders the assembly of rat Abeta dimers into oligomeric aggregates. Thus, the differences in the structure of zinc-binding sites of human and rat Abeta(1-16), their ability to form regular cross-monomer bonds, and the orientation of their hydrophobic C-tails could be responsible for the resistance of rats to Alzheimer's disease. NMR solution structure of rat abeta(1-16): toward understanding the mechanism of rats' resistance to Alzheimer's disease.,Istrate AN, Tsvetkov PO, Mantsyzov AB, Kulikova AA, Kozin SA, Makarov AA, Polshakov VI Biophys J. 2012 Jan 4;102(1):136-43. Epub 2012 Jan 3. PMID:22225807[1] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. References
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