Biology subjects

Saluri, M.

Publications and source records attributed to Saluri, M..

3 recordsLinked to original sources

bioRxiv2024

AI-first structural identification of pathogenic protein targets

The likelihood for pandemics is increasing as the world population grows and becomes more interconnected. Obtaining structural knowledge of protein-protein interactions between a pathogen and its host can inform pathogenic mechanisms and treatment or vaccine design. Currently, there are 52 nonredundant human-pathogen interactions with known structure in the PDB, although there are 21064 with experimental support in the HPIDB, meaning that only 0.2% of known interactions have known structure. Recent improvements in structure prediction of protein complexes based on AlphaFold have made it possible to model heterodimeric complexes with very high accuracy. However, it is not known how this translates to host-pathogen interactions which share a different evolutionary relationship. Here, we analyse the structural protein-protein interaction network between ten different pathogens and their human host. We predict the structure of 9452 human-pathogen interactions of which only 10 have known structure. We find that we can model 30 interactions with an expected TM-score of [≥]0.9, expanding the structural knowledge in these networks three-fold. We select the highly-scoring Francisella tularensis dihydroprolyl dehydrogenase (IPD) complex with human immunoglobulin Kappa constant (IGKC) for detailed analysis with homology modeling and native mass spectrometry. Our results confirm the predicted 1:2:1 heterotetrameric complex with potential implications for bacterial immune response evasion. We are entering a new era where structure prediction can be used to guide vaccine and drug development towards new pathogenic targets in very short time frames.

bioinformatics↗

bioRxiv2022

A grappling hook interaction balances self-assembly and chaperone activity of Nucleophosmin 1

How the self-assembly of partially disordered proteins generates functional compartments in the cytoplasm and particularly in the nucleus is poorly understood. Nucleophosmin 1 (NPM1) is an abundant nucleolar protein that forms large oligomers which provide the scaffold for ribosome assembly but also prevent protein aggregation as part of the cellular stress response. Examining the relationship between the self-assembly and chaperone activity of NPM1, we find that oligomerization of full-length NPM1 modulates its ability to retard amyloid formation in vitro. Machine learning and cryo-electron microscopy reveal fuzzy interactions between the disordered region and the C-terminal nucleotide-binding domain that cross-link NPM1 pentamers into oligomers. Ribosomal peptides mediate in a tighter association within the oligomers, reducing their capacity to prevent amyloid formation. We conclude that NPM1 uses a "grappling hook" interaction to form a network-like structure whose chaperone activity is tuned by basic proteins, suggesting a regulatory mechanism for the nucleolar stress response.

biophysics↗

bioRxiv2021

A spindle and thread-mechanism unblocks translation of N-terminally disordered proteins

Protein disorder is a major hurdle for structural biology. A prominent example is the tumour suppressor p53, whose low expression levels and poor conformational stability due to a high degree of disorder pose major challenges to the development of cancer therapeutics. Here, we address these issues by fusing p53 to an engineered spider silk domain termed NT*. The chimeric protein displays highly efficient translation in vitro and in E. coli and is fully active in human cancer cells. The transmission electron microscopy structure and native mass spectrometry reveal that the full-length p53 fusion protein adopts a compact conformation. Molecular dynamics simulations show that the disordered transactivation domain of p53 is wound around the NT* domain via a series of folding events, resulting in a globular structure. We find that expression of B-Raf, another partially disordered cancer target, is similarly enhanced by fusion to NT*. In summary, we demonstrate how inducing co-translational folding via a molecular "spindle and thread" mechanism can overcome poor translation efficiency of partially disordered proteins.

biochemistry↗