Qr: author:"Maino Tahara"
Showing 1 - 4 of 4 results
1.
Optogenetic and temperature-dependent modulation of vesicular stomatitis virus polymerase activity by an intramolecular dimerizer.
Abstract:
Optogenetic dimerization modules are widely used to regulate protein function, yet their behaviour within folded enzymes remains incompletely understood. Here, we engineered vesicular stomatitis virus by inserting an intramolecularly tethered light-inducible dimerizer into the viral RNA-dependent RNA polymerase [large (L) protein], enabling assessment of its effects on early viral transcription and viral replication. Blue light illumination enhanced viral replication, but reduced temperature produced a similar increase in viral replication even in the absence of light. In addition, a thermally stabilized dimerizer variant supported robust replication under dark conditions. These observations suggest that early viral transcription and viral replication are influenced by the structural and biophysical properties of the inserted dimerizer and their temperature dependence, rather than by light alone. Structural modelling suggested that permissive insertion sites are located within or adjacent to regions with low predicted Local Distance Difference Test (pLDDT) scores, whereas non-permissive insertions showed greater predicted local structural deviations, particularly in the capping domain. Although these analyses are based on predicted structures, the observed structural differences are consistent with the functional differences among insertion sites. Together, our results show that intramolecular optogenetic modules enable light- and temperature-dependent modulation of early viral transcription and replication. While the structural analyses are based on predicted models, they provide a useful framework for identifying permissive insertion sites and generate testable hypotheses regarding how the structural and biophysical properties of the inserted dimerizer may influence polymerase function.
2.
Optical Control of Mononegavirus Gene Expression and Replication.
Abstract:
Mononegaviruses are promising tools as oncolytic and transgene vectors for gene therapy and regenerative medicine. However, when mononegaviruses are used for therapeutic applications, the viral activity must be strictly controlled due to concerns about toxicity and severe side effects. With this technology, mononegavirus vectors can be grown where they are intended and can be easily removed when they are no longer needed. In particular, a photoswitch protein called Magnet (consisting of two magnet domains) is incorporated into the hinge region between the connector and methyltransferase domains of the mononegavirus polymerase protein (L protein) to disrupt the L protein functions. Blue light (470 ± 20 nm) irradiation causes the dimerization of the two magnet domains, and the L protein is restored to activity, allowing viral gene expression and virus replication. Since the magnet domains' dimerization is reversible, viral gene expression and replication cease when blue light irradiation is stopped.
3.
Generation of a photocontrollable recombinant bovine parainfluenza virus type 3.
Abstract:
Bovine parainfluenza virus type 3 (BPIV3) is a promising vaccine vector against various respiratory virus infections, including the human PIV3, respiratory syncytial virus, and severe acute respiratory syndrome-coronavirus 2 infections. In this study, we combined the Magnet system and reverse genetic approach to generate photocontrollable BPIV3. An optically controllable Magnet gene was inserted into the H2 region of the BPIV3 large protein gene, which encodes an RNA-dependent RNA polymerase. The generated photocontrollable BPIV3 grew in specific regions of the cell sheet only when illuminated with blue light, suggesting that spatiotemporal control can aid in safe clinical applications of BPIV3.
4.
Photocontrollable mononegaviruses.
Abstract:
Mononegaviruses are promising tools as oncolytic vectors and transgene delivery vectors for gene therapy and regenerative medicine. By using the Magnet proteins, which reversibly heterodimerize upon blue light illumination, photocontrollable mononegaviruses (measles and rabies viruses) were generated. The Magnet proteins were inserted into the flexible domain of viral polymerase, and viruses showed strong replication and oncolytic activities only when the viral polymerases were activated by blue light illumination.