New Techniques to Study Intracellular Receptors in Living Cells: Insights Into RIG-I-Like Receptor Signaling.

This review discusses new developments in Förster resonance energy transfer (FRET) microscopy and its application to cellular receptors. The method is based on the kinetic theory of FRET, which can be used to predict FRET not only in dimers, but also higher order oligomers of donor and acceptor fluorophores. Models based on such FRET predictions can be fit to observed FRET efficiency histograms (also called FRET spectrograms) and used to estimate intracellular binding constants, free energy values, and stoichiometries.

Quantitative microspectroscopic imaging reveals viral and cellular RNA helicase interactions in live cells.

Human cells detect RNA viruses through a set of helicases called RIG-I-like receptors (RLRs) that initiate the interferon response via a mitochondrial signaling complex. Many RNA viruses also encode helicases, which are sometimes covalently linked to proteases that cleave signaling proteins. One unresolved question is how RLRs interact with each other and with viral proteins in cells.

Simultaneously Targeting the NS3 Protease and Helicase Activities for More Effective Hepatitis C Virus Therapy.

This study examines the specificity and mechanism of action of a recently reported hepatitis C virus (HCV) nonstructural protein 3 (NS3) helicase-protease inhibitor (HPI), and the interaction of HPI with the NS3 protease inhibitors telaprevir, boceprevir, danoprevir, and grazoprevir. HPI most effectively reduced cellular levels of subgenomic genotype 4a replicons, followed by genotypes 3a and 1b replicons. HPI had no effect on HCV genotype 2a or dengue virus replicon levels.

Experimental autoimmune encephalomyelitis induction in peptidylarginine deiminase 2 knockout mice.

During the development of multiple sclerosis the destruction of the myelin sheath surrounding the neurites is accompanied by citrullination of several central nervous system (CNS) proteins, including myelin basic protein and glial fibrillary acidic protein. In experimental autoimmune encephalomyelitis (EAE), a disease induced in animals by immunization with proteins or peptides from the CNS, the animals develop symptoms similar to multiple sclerosis (MS). The increased levels of citrullinated CNS proteins associated with MS are also observed during the development of EAE.