Molecular Stressors Engender Protein Connectivity Dysfunction through Aberrant N-Glycosylation of a Chaperone.

Stresses associated with disease may pathologically remodel the proteome by both increasing interaction strength and altering interaction partners, resulting in proteome-wide connectivity dysfunctions. Chaperones play an important role in these alterations, but how these changes are executed remains largely unknown. Our study unveils a specific N-glycosylation pattern used by a chaperone, Glucose-regulated protein 94 (GRP94), to alter its conformational fitness and stabilize a state most permissive for stable interactions with proteins at the plasma membrane. This "protein assembly mutation' remodels protein networks and properties of the cell. We show in cells, human specimens, and mouse xenografts that proteome connectivity is restorable by inhibition of the N-glycosylated GRP94 variant. In summary, we provide biochemical evidence for stressor-induced chaperone-mediated protein mis-assemblies and demonstrate how these alterations are actionable in disease.

Whole-genome optical mapping reveals a mis-assembly between two rRNA operons of Corynebacterium pseudotuberculosis strain 1002.

BACKGROUND: Studies have detected mis-assemblies in genomes of the species Corynebacterium pseudotuberculosis. These new discover have been possible due to the evolution of the Next-Generation Sequencing platforms, which have provided sequencing with accuracy and reduced costs. In addition, the improving of techniques for construction of high accuracy genomic maps, for example, Whole-genome mapping (WGM) (OpGen Inc), have allow high-resolution assembly that can detect large rearrangements. RESULTS: In this work, we present the resequencing of Corynebacterium pseudotuberculosis strain 1002 (Cp1002). Cp1002 was the first strain of this species sequenced in Brazil, and its genome has been used as model for several studies in silico of caseous lymphadenitis disease. The sequencing was performed using the platform Ion PGM and fragment library (200 bp kit). A restriction map was constructed, using the technique of WGM with the enzyme KpnI. After the new assembly process, using WGM as scaffolder, we detected a large inversion with size bigger than one-half of genome. A specific analysis using BLAST and NR database shows that the inversion occurs between two homology RNA ribosomal regions. CONCLUSION: In conclusion, the results showed by WGM could be used to detect mismatches in assemblies, providing genomic maps with high resolution and allow assemblies with more accuracy and completeness. The new assembly of C. pseudotuberculosis was deposited in GenBank under the accession no. CP012837.