1
|
Chen G, Wang Y, Zheng Z, Jiang W, Leppert A, Zhong X, Belorusova A, Siegal G, Jegerschöld C, Koeck PJB, Abelein A, Hebert H, Knight SD, Johansson J. Molecular basis for different substrate-binding sites and chaperone functions of the BRICHOS domain. Protein Sci 2024; 33:e5063. [PMID: 38864729 PMCID: PMC11168071 DOI: 10.1002/pro.5063] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2024] [Revised: 05/10/2024] [Accepted: 05/13/2024] [Indexed: 06/13/2024]
Abstract
Proteins can misfold into fibrillar or amorphous aggregates and molecular chaperones act as crucial guardians against these undesirable processes. The BRICHOS chaperone domain, found in several otherwise unrelated proproteins that contain amyloidogenic regions, effectively inhibits amyloid formation and toxicity but can in some cases also prevent non-fibrillar, amorphous protein aggregation. Here, we elucidate the molecular basis behind the multifaceted chaperone activities of the BRICHOS domain from the Bri2 proprotein. High-confidence AlphaFold2 and RoseTTAFold predictions suggest that the intramolecular amyloidogenic region (Bri23) is part of the hydrophobic core of the proprotein, where it occupies the proposed amyloid binding site, explaining the markedly reduced ability of the proprotein to prevent an exogenous amyloidogenic peptide from aggregating. However, the BRICHOS-Bri23 complex maintains its ability to form large polydisperse oligomers that prevent amorphous protein aggregation. A cryo-EM-derived model of the Bri2 BRICHOS oligomer is compatible with surface-exposed hydrophobic motifs that get exposed and come together during oligomerization, explaining its effects against amorphous aggregation. These findings provide a molecular basis for the BRICHOS chaperone domain function, where distinct surfaces are employed against different forms of protein aggregation.
Collapse
Affiliation(s)
- Gefei Chen
- Department of Biosciences and NutritionKarolinska InstitutetHuddingeSweden
- Department of Cell and Molecular BiologyUppsala UniversityUppsalaSweden
| | - Yu Wang
- Department of Biosciences and NutritionKarolinska InstitutetHuddingeSweden
- College of Wildlife and Protected Area, Northeast Forestry UniversityHarbinChina
| | - Zihan Zheng
- Department of Biosciences and NutritionKarolinska InstitutetHuddingeSweden
- Department of PharmacologyXi'an Jiaotong UniversityXi'anChina
| | - Wangshu Jiang
- Department of Cell and Molecular BiologyUppsala UniversityUppsalaSweden
| | - Axel Leppert
- Department of Biosciences and NutritionKarolinska InstitutetHuddingeSweden
- Present address:
Department of Microbiology, Tumour and Cell BiologyKarolinska InstitutetSolnaSweden
| | - Xueying Zhong
- Department of Biomedical Engineering and Health Systems, School of Engineering Sciences in Chemistry, Biotechnology and HealthKTH Royal Institute of TechnologyHuddingeSweden
| | | | | | - Caroline Jegerschöld
- Department of Biomedical Engineering and Health Systems, School of Engineering Sciences in Chemistry, Biotechnology and HealthKTH Royal Institute of TechnologyHuddingeSweden
| | - Philip J. B. Koeck
- Department of Biomedical Engineering and Health Systems, School of Engineering Sciences in Chemistry, Biotechnology and HealthKTH Royal Institute of TechnologyHuddingeSweden
| | - Axel Abelein
- Department of Biosciences and NutritionKarolinska InstitutetHuddingeSweden
| | - Hans Hebert
- Department of Biomedical Engineering and Health Systems, School of Engineering Sciences in Chemistry, Biotechnology and HealthKTH Royal Institute of TechnologyHuddingeSweden
| | - Stefan D. Knight
- Department of Cell and Molecular BiologyUppsala UniversityUppsalaSweden
| | - Jan Johansson
- Department of Biosciences and NutritionKarolinska InstitutetHuddingeSweden
| |
Collapse
|
2
|
Kumar R, Le Marchand T, Adam L, Bobrovs R, Chen G, Fridmanis J, Kronqvist N, Biverstål H, Jaudzems K, Johansson J, Pintacuda G, Abelein A. Identification of potential aggregation hotspots on Aβ42 fibrils blocked by the anti-amyloid chaperone-like BRICHOS domain. Nat Commun 2024; 15:965. [PMID: 38302480 PMCID: PMC10834949 DOI: 10.1038/s41467-024-45192-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2023] [Accepted: 01/17/2024] [Indexed: 02/03/2024] Open
Abstract
Protein misfolding can generate toxic intermediates, which underlies several devastating diseases, such as Alzheimer's disease (AD). The surface of AD-associated amyloid-β peptide (Aβ) fibrils has been suggested to act as a catalyzer for self-replication and generation of potentially toxic species. Specifically tailored molecular chaperones, such as the BRICHOS protein domain, were shown to bind to amyloid fibrils and break this autocatalytic cycle. Here, we identify a site on the Aβ42 fibril surface, consisting of three C-terminal β-strands and particularly the solvent-exposed β-strand stretching from residues 26-28, which is efficiently sensed by a designed variant of Bri2 BRICHOS. Remarkably, while only a low amount of BRICHOS binds to Aβ42 fibrils, fibril-catalyzed nucleation processes are effectively prevented, suggesting that the identified site acts as a catalytic aggregation hotspot, which can specifically be blocked by BRICHOS. Hence, these findings provide an understanding how toxic nucleation events can be targeted by molecular chaperones.
Collapse
Affiliation(s)
- Rakesh Kumar
- Department of Biosciences and Nutrition, Karolinska Institutet, 141 83, Huddinge, Sweden
| | - Tanguy Le Marchand
- Université de Lyon, Centre de Resonance Magnétique Nucléaire (CRMN) à Très Hauts Champs de Lyon (UMR 5082 - CNRS, ENS Lyon, UCB Lyon 1), 69100, Villeurbanne, France
| | - Laurène Adam
- Department of Biosciences and Nutrition, Karolinska Institutet, 141 83, Huddinge, Sweden
| | - Raitis Bobrovs
- Department of Physical Organic Chemistry, Latvian Institute of Organic Synthesis, Riga, Latvia
| | - Gefei Chen
- Department of Biosciences and Nutrition, Karolinska Institutet, 141 83, Huddinge, Sweden
| | - Jēkabs Fridmanis
- Department of Physical Organic Chemistry, Latvian Institute of Organic Synthesis, Riga, Latvia
| | - Nina Kronqvist
- Department of Biosciences and Nutrition, Karolinska Institutet, 141 83, Huddinge, Sweden
| | - Henrik Biverstål
- Department of Biosciences and Nutrition, Karolinska Institutet, 141 83, Huddinge, Sweden
| | - Kristaps Jaudzems
- Department of Physical Organic Chemistry, Latvian Institute of Organic Synthesis, Riga, Latvia
| | - Jan Johansson
- Department of Biosciences and Nutrition, Karolinska Institutet, 141 83, Huddinge, Sweden
| | - Guido Pintacuda
- Université de Lyon, Centre de Resonance Magnétique Nucléaire (CRMN) à Très Hauts Champs de Lyon (UMR 5082 - CNRS, ENS Lyon, UCB Lyon 1), 69100, Villeurbanne, France
| | - Axel Abelein
- Department of Biosciences and Nutrition, Karolinska Institutet, 141 83, Huddinge, Sweden.
| |
Collapse
|