Mahato, R. | Search bioRxiv

bioRxiv2026

Integrative structure determination of a human mitochondrial contact site and cristae organizing system (MICOS) sub-assembly

The Mitochondrial contact site and Cristae Organizing System (MICOS) complex is an inner mitochondrial membrane (IMM) assembly present at the cristae junction. It is responsible for regulating cristae formation and remodeling. However, its structure is not known. We applied Bayesian integrative structure determination to characterize the structure of the Mic60, Mic19, Mic10, and Mic13-containing MICOS complex combining AlphaFold predictions with data from crosslinking mass spectrometry, biochemical assays, electron tomography, homology modeling, and sequence alignments. The integrative structure revealed novel mutual interfaces among Mic10N,C, Mic60LBS1,LBS2,mitofilin, and Mic13central,C, which were experimentally validated. Several likely-pathogenic missense mutations also localize to these novel interfaces, highlighting their importance. Our results indicate that Mic13 likely facilitates MICOS assembly by binding Mic10 in the IMM-proximal region and Mic60 in the intermembrane space. Taken together, our integrative approach sheds light on the structure and assembly of the MICOS complex.

bioinformatics↗

bioRxiv2024

Snake venom-inspired novel peptides protect Caenorhabditis elegans against paraquat induced Parkinson's pathology

The in vivo protective mechanisms of two low molecular mass ([~]1.4 kDa) novel custom peptides (CPs) against paraquat (PT)-induced neurodegenerative dysfunction in the Caenorhabditis elegans model were deciphered. CPs prevent the PT binding to the nerve ring adjacent to the pharynx in C. elegans (N2 strain) by stable and high-affinity binding to the tyrosine-protein kinase receptor CAM-1, resulting in significant inhibition of PT-induced toxicity by reducing enhanced reactive oxygen species production, mitochondrial membrane depolarization, and chemosensory dysfunction. The CPs inhibited PT-induced dopaminergic (DAergic) neuron degeneration and alpha-synuclein aggregation, the hallmarks of Parkinsons Disease, in transgenic BZ555 and NL5901 strains of C. elegans. The transcriptomic, functional proteomics, and quantitative reverse transcription-polymerase chain reaction (qRT-PCR) analyses show that CPs prevented the increased expression of the genes involved in the skn-1 downstream pathway, thereby restoring PT-mediated oxidative stress, apoptosis, and neuronal damage in C. elegans. The CPs ability to repair PT-induced damage was demonstrated by a network of gene expression profiles illustrating the molecular relationships between the regulatory proteins. Further, CPs (10 mg/kg, parental route) did not show toxicity or induce inflammatory mediators in the mouse model.

neuroscience↗