Cargando…
Metal Binding Properties of the N-Terminus of the Functional Amyloid Orb2
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...
Autores principales: | , , , , , , |
---|---|
Formato: | Online Artículo Texto |
Lenguaje: | English |
Publicado: |
MDPI
2017
|
Materias: | |
Acceso en línea: | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5618238/ https://www.ncbi.nlm.nih.gov/pubmed/28763009 http://dx.doi.org/10.3390/biom7030057 |
_version_ | 1783267144160509952 |
---|---|
author | Bajakian, Thalia H. Cervantes, Silvia A. Soria, Maria A. Beaugrand, Maïwenn Kim, Ji Yun Service, Rachel J. Siemer, Ansgar B. |
author_facet | Bajakian, Thalia H. Cervantes, Silvia A. Soria, Maria A. Beaugrand, Maïwenn Kim, Ji Yun Service, Rachel J. Siemer, Ansgar B. |
author_sort | Bajakian, Thalia H. |
collection | PubMed |
description | 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 Ni(2+) 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 Ni(2+) binding induces the aggregating of Orb2 into structures that are distinct from the amyloid fibrils formed in the absence of Ni(2+). These data suggest that transition metal binding might be important for the function of Orb2 and potentially long-term memory in Drosophila. |
format | Online Article Text |
id | pubmed-5618238 |
institution | National Center for Biotechnology Information |
language | English |
publishDate | 2017 |
publisher | MDPI |
record_format | MEDLINE/PubMed |
spelling | pubmed-56182382017-09-29 Metal Binding Properties of the N-Terminus of the Functional Amyloid Orb2 Bajakian, Thalia H. Cervantes, Silvia A. Soria, Maria A. Beaugrand, Maïwenn Kim, Ji Yun Service, Rachel J. Siemer, Ansgar B. Biomolecules Article 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 Ni(2+) 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 Ni(2+) binding induces the aggregating of Orb2 into structures that are distinct from the amyloid fibrils formed in the absence of Ni(2+). These data suggest that transition metal binding might be important for the function of Orb2 and potentially long-term memory in Drosophila. MDPI 2017-08-01 /pmc/articles/PMC5618238/ /pubmed/28763009 http://dx.doi.org/10.3390/biom7030057 Text en © 2017 by the authors. Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (http://creativecommons.org/licenses/by/4.0/). |
spellingShingle | Article Bajakian, Thalia H. Cervantes, Silvia A. Soria, Maria A. Beaugrand, Maïwenn Kim, Ji Yun Service, Rachel J. Siemer, Ansgar B. Metal Binding Properties of the N-Terminus of the Functional Amyloid Orb2 |
title | Metal Binding Properties of the N-Terminus of the Functional Amyloid Orb2 |
title_full | Metal Binding Properties of the N-Terminus of the Functional Amyloid Orb2 |
title_fullStr | Metal Binding Properties of the N-Terminus of the Functional Amyloid Orb2 |
title_full_unstemmed | Metal Binding Properties of the N-Terminus of the Functional Amyloid Orb2 |
title_short | Metal Binding Properties of the N-Terminus of the Functional Amyloid Orb2 |
title_sort | metal binding properties of the n-terminus of the functional amyloid orb2 |
topic | Article |
url | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5618238/ https://www.ncbi.nlm.nih.gov/pubmed/28763009 http://dx.doi.org/10.3390/biom7030057 |
work_keys_str_mv | AT bajakianthaliah metalbindingpropertiesofthenterminusofthefunctionalamyloidorb2 AT cervantessilviaa metalbindingpropertiesofthenterminusofthefunctionalamyloidorb2 AT soriamariaa metalbindingpropertiesofthenterminusofthefunctionalamyloidorb2 AT beaugrandmaiwenn metalbindingpropertiesofthenterminusofthefunctionalamyloidorb2 AT kimjiyun metalbindingpropertiesofthenterminusofthefunctionalamyloidorb2 AT servicerachelj metalbindingpropertiesofthenterminusofthefunctionalamyloidorb2 AT siemeransgarb metalbindingpropertiesofthenterminusofthefunctionalamyloidorb2 |