Sven Saupe, Institute of Cellular Biochemistry and Genetics, UMR 5095

I am CNRS research director, geneticist at the IBGC (Institute of Biochemistry and Cellular Genetics UMR 5095) and head of the "Non-Self Recognition in Fungi" team. We are interested in the mechanisms governing the recognition of non-self in this vast branch of the eukaryotic tree. We study various aspects of the detection and response to noself in fungi, with particular emphasis on a family of cytoplasmic receptors called NLRs (Nod-like receptors) that control innate immunity and other processes of biotic interaction in animal and plant lines. NLR proteins are intracellular receptors that constitute a conserved component of the innate immune system of cellular organisms. In fungi, NLRs are characterized by a wide diversity of architectures and the presence of amyloid signaling.

Amyloids are implicated in many diseases due to protein misfolding (Alzheimer's and Parkinson's diseases and type 2 diabetes). Functional amyloids involved in the control of cell death regulatory mechanisms have so far only been characterized in fungi and mammals. The Infranalytics project aimed to characterize a functional amyloid involved in NLR activation in bacteria. A method of choice for studying amyloids at the atomic level is solid-state nuclear magnetic resonance (NMR). The development of isotopic labeling strategies has greatly enhanced the power of solid-state NMR in structural studies, as the labeling patterns allow selective retrieval of desired information (i.e. specific position of labeled nuclei ¹³This ¹⁵N in amyloid proteins). This project was developed in collaboration with Antoine Loquet.

We have identified a number of bacterial amyloid signaling motifs in bacterial genomes that we call “tem BASS” (bacterial amyloid signaling sequence). During this Infranalytics project, we used solid-state NMR to assign the rigid core of the BASS1 protein to its fibrillar state.

Find out more: https://doi.org/10.1016/j.jmb.2020.10.004 

Platform used: CBMN - IECB (Bordeaux)