MATRIX BIOLOGY
Within the bacterial domain actinomycetes have an unusual life cycle. These microorganisms colonise dead and living organic material by means of hyphae that grow at their apices. These hyphae are part of an interconnected network, called a mycelium. After a period of vegetative growth, hyphae grow out of the substrate into the air. These aerial hyphae differentiate into chains of spores that, after dispersal, give rise to new mycelia. Actinomycetes may also adhere to surfaces. The Claessen lab is interested in the mechanisms enabling actinomycetes to form reproductive aerial structures or to attach to surfaces. These processes depend on the formation of an extracellular matrix consisting of glycans and proteins. Notably, two classes of proteins, called chaplins and rodlins, function by assembling into so-called amyloid fibrils. Such fibrils are often associated with severe diseases in mammals (like Alzheimer’s). Our work has demonstrated that amyloids can also be beneficial to microbes enabling them to mechanically invade abiotic and biotic substrates.
