Metal Binding Properties of the N-Terminus of the Functional Amyloid Orb2
| Autor: | Maïwenn Beaugrand, Ansgar B. Siemer, Silvia A. Cervantes, Thalia H. Bajakian, Maria A. Soria, Ji Yun Kim |
|---|---|
| Jazyk: | angličtina |
| Rok vydání: | 2017 |
| Předmět: |
0301 basic medicine
Amyloid Glutamine Cytoplasmic polyadenylation element lcsh:QR1-502 Plasma protein binding Calorimetry Biochemistry Article lcsh:Microbiology CPEB amyloid protein–metal interaction aggregation ITC thioflavin T fluorescence 03 medical and health sciences 0302 clinical medicine Nickel Animals Drosophila Proteins Histidine Binding site Molecular Biology mRNA Cleavage and Polyadenylation Factors Binding Sites biology Chemistry Circular Dichroism Binding protein Isothermal titration calorimetry Microscopy Electron Drosophila melanogaster 030104 developmental biology Mutagenesis Site-Directed biology.protein Biophysics 030217 neurology & neurosurgery Protein Binding Transcription Factors Binding domain |
| Zdroj: | Biomolecules; Volume 7; Issue 3; Pages: 57 Biomolecules, Vol 7, Iss 3, p 57 (2017) Biomolecules |
| ISSN: | 2218-273X |
| DOI: | 10.3390/biom7030057 |
| Popis: | The cytoplasmic polyadenylation element binding protein (CPEB) homologue Orb2 is a functional amyloid that plays a key regulatory role for long-term memory in Drosophila. Orb2 has a glutamine, histidine-rich (Q/H-rich) domain that resembles the Q/H-rich, metal binding domain of the Hpn-like protein (Hpnl) found in Helicobacter pylori. In the present study, we used chromatography and isothermal titration calorimetry (ITC) to show that the Q/H-rich domain of Orb2 binds Ni2+ and other transition metals ions with μM affinity. Using site directed mutagenesis, we show that several histidine residues are important for binding. In particular, the H61Y mutation, which was previously shown to affect the aggregation of Orb2 in cell culture, completely inhibited metal binding of Orb2. Finally, we used thioflavin T fluorescence and electron microscopy images to show that Ni2+ binding induces the aggregating of Orb2 into structures that are distinct from the amyloid fibrils formed in the absence of Ni2+. These data suggest that transition metal binding might be important for the function of Orb2 and potentially long-term memory in Drosophila. |
| Databáze: | OpenAIRE |
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