Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Scientists uncover amyloid-like proteins in bacteria

09.07.2003


Independent research groups have uncovered a new class of proteins, called the chaplins, that function like amyloid fibrils to allow reproductive growth in the bacterium Streptomyces coelicolor. Amyloid proteins are most commonly recognized for their role in Alzheimer’s disease, where they aggregate into insoluble, mesh-like plaques in the brains of Alzheimer’s patients. This finding reveals an unprecedented role for amyloid-like proteins in Gram-positive bacteria.



S. coelicolor is a soil-dwelling bacterium that, along with its relatives, produces the majority of naturally derived antibiotics (e.g., tetracycline and erythromycin), as well as many antitumor, antifungal, and immunosuppressant agents. Unlike most other prokaryotes, S. coelicolor has a complex life cycle, producing two different cell types depending upon environmental conditions: vegetative substrate hyphae that grow in moist soil, and aerial hyphae that grow in air and give rise to reproductive spores.

As published in the July 15th issue of Genes & Development, independent research carried out by Dr. Marie Elliot, Dr. Mark Buttner and colleagues at the John Innes Centre (UK) and Stanford University (USA), and by Dennis Claessen, Dr. Lubbert Dijkhuizen, Dr. Han Wösten and colleagues at the University of Groningen and the University of Utrecht (Netherlands), have identified the chaplin protein family as essential mediators of aerial S. coelicolor growth. The research in the Netherlands was funded by a grant of the National Programme EET (Economy, Ecology and Technology) to find biological alternatives for the environmentally harmful antifouling compounds used today on ships.


Although the two groups used different experimental approaches to identify genes involved in aerial hyphae formation, both reached a common conclusion. Both groups discovered a previously unidentified family of hydrophobic, cell-surface proteins whose eight members (chaplins A-H) are necessary for aerial hyphae formation. In independent experiments, Elliot et al. and Claessen et al. demonstrated that streptomycetes lacking specific chaplin genes were unable to erect aerial hyphae, but that this condition could be restored through the application of exogenous chaplin proteins.

The authors suggest that coating of the aerial hyphae by chaplin proteins may confer hydrophobicity to these structures, allowing them to grow into the air and possibly even preventing back-growth into the moist soil. "The hydrophobic nature of aerial structures could be an ideal property to prevent organisms from fouling in shipping. In our aim to find biological alternatives for antifouling compounds we are currently studying the antifouling properties of these highly surface active proteins," explains Dennis Claessen, of the University of Groningen.

Dr. Dijkhuizen’s group further investigated the role of the chaplin proteins at the soil/air interface, finding that chaplin genes E and H are also expressed in the submerged substrate hyphae. The researchers went on to show that a mixture of chaplin proteins D - H self-assembled into amyloid-like fibrils at the soil/air interface, suggesting that chaplins D-H may help lower the water surface tension to facilitate the breakthrough of aerial structures into air.

The identification of the chaplin proteins in Streptomyces potentially has important implications for its use by the pharmaceutical industry. "Chaplins adopt an amyoid-like structure, and could therefore be used as a model system to find molecules that prevent formation of amyloid fibrils" said Dennis Claessen and Dr. Marie Elliot. Furthermore, this landmark discovery of functional amyloid-like fibrils in Gram-positive bacteria illustrates the diversity of amyloid function across genomes.

Heather Cosel | EurekAlert!

More articles from Life Sciences:

nachricht How gut bacteria can make us ill
18.01.2017 | Helmholtz-Zentrum für Infektionsforschung

nachricht Nanoparticle Exposure Can Awaken Dormant Viruses in the Lungs
16.01.2017 | Helmholtz Zentrum München - Deutsches Forschungszentrum für Gesundheit und Umwelt

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: How gut bacteria can make us ill

HZI researchers decipher infection mechanisms of Yersinia and immune responses of the host

Yersiniae cause severe intestinal infections. Studies using Yersinia pseudotuberculosis as a model organism aim to elucidate the infection mechanisms of these...

Im Focus: Interfacial Superconductivity: Magnetic and superconducting order revealed simultaneously

Researchers from the University of Hamburg in Germany, in collaboration with colleagues from the University of Aarhus in Denmark, have synthesized a new superconducting material by growing a few layers of an antiferromagnetic transition-metal chalcogenide on a bismuth-based topological insulator, both being non-superconducting materials.

While superconductivity and magnetism are generally believed to be mutually exclusive, surprisingly, in this new material, superconducting correlations...

Im Focus: Studying fundamental particles in materials

Laser-driving of semimetals allows creating novel quasiparticle states within condensed matter systems and switching between different states on ultrafast time scales

Studying properties of fundamental particles in condensed matter systems is a promising approach to quantum field theory. Quasiparticles offer the opportunity...

Im Focus: Designing Architecture with Solar Building Envelopes

Among the general public, solar thermal energy is currently associated with dark blue, rectangular collectors on building roofs. Technologies are needed for aesthetically high quality architecture which offer the architect more room for manoeuvre when it comes to low- and plus-energy buildings. With the “ArKol” project, researchers at Fraunhofer ISE together with partners are currently developing two façade collectors for solar thermal energy generation, which permit a high degree of design flexibility: a strip collector for opaque façade sections and a solar thermal blind for transparent sections. The current state of the two developments will be presented at the BAU 2017 trade fair.

As part of the “ArKol – development of architecturally highly integrated façade collectors with heat pipes” project, Fraunhofer ISE together with its partners...

Im Focus: How to inflate a hardened concrete shell with a weight of 80 t

At TU Wien, an alternative for resource intensive formwork for the construction of concrete domes was developed. It is now used in a test dome for the Austrian Federal Railways Infrastructure (ÖBB Infrastruktur).

Concrete shells are efficient structures, but not very resource efficient. The formwork for the construction of concrete domes alone requires a high amount of...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

12V, 48V, high-voltage – trends in E/E automotive architecture

10.01.2017 | Event News

2nd Conference on Non-Textual Information on 10 and 11 May 2017 in Hannover

09.01.2017 | Event News

Nothing will happen without batteries making it happen!

05.01.2017 | Event News

 
Latest News

Water - as the underlying driver of the Earth’s carbon cycle

17.01.2017 | Earth Sciences

Interfacial Superconductivity: Magnetic and superconducting order revealed simultaneously

17.01.2017 | Materials Sciences

Smart homes will “LISTEN” to your voice

17.01.2017 | Architecture and Construction

VideoLinks
B2B-VideoLinks
More VideoLinks >>>