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Biology subjects

Kamura, T.

Publications and source records attributed to Kamura, T..

3 recordsLinked to original sources

Inducible degradation of endogenous proteins by AlissAID system and development of a photoactivatable inducer.

Protein analysis strategies involving targeted protein degradation are powerful approaches to determine gene functions. Auxin-inducible degron (AID) is among the most widely used methods for target protein knockdown. This system enables the rapid depletion of AID-tagged target proteins in an auxin-dependent manner. Various improved AID methods have been developed to date; however, the requirement to tag the target protein remains a common challenge. Here, we demonstrated the efficiency of the affinity-linker-based super-sensitive AID system for condition-knockdown of target proteins in cultured animal cells and mouse embryos. This system combines the improved AID method with small-molecule antibodies, enabling the control of GFP and mCherry fusion proteins. Additionally, this system can be used to degrade endogenous targets, such as Ras proteins. We also developed a novel inducer, caged 5-adamantyl-IAA, that precisely controlled targeted protein degradation under light irradiation. This advanced technique aids in the degradation of endogenous proteins of interest and can be used to develop new technologies for localized protein degradation.

cell biology↗

In Vivo mRNA Hacking with Staple Oligomers Prevents Myocardial Hypertrophy

Summary paragraphThe elucidation of gene-silencing mechanisms by RNA interference (RNAi) and antisense oligomers has drawn increasing attention to nucleic acid medicine. However, several challenges remain to be overcome, such as in vivo stability1, target selectivity 2,3, drug delivery4,5, and induced innate immunity6. Here, we report a new, versatile, and highly-selective method to hack RNA by controlling RNA structure using short oligonucleotides (RNA hacking: RNAh) in living cells. The oligonucleotide, named Staple oligomer, hybridizes specifically to a target mRNA and artificially induces an RNA higher-order structure, RNA G-quadruplex (RGq)7, on the mRNA. As a result, the RGq allows effective suppression of the target protein translation. This technology does not require cooperation with bioprocesses including enzymatic reactions as in RNAi or antisense technologies, permitting the introduction of artificial nucleic acids into Staple oligomers to increase their in vivo stability without compromising their effectiveness. The method was validated by translational regulation of the mRNAs of TPM3, MYD88, and TRPC6, in a cell-free system and in living mammalian cells. In vivo application of the technology to TRPC6 mRNA allowed us to prevent cardiac hypertrophy in transverse aortic constriction (TAC)-treated mice with no detectable off-target effects. This technology provides new insights into gene therapy after RNAi and antisense technologies.

molecular biology↗

A super sensitive auxin-inducible degron system with an engineered auxin-TIR1 pair

Auxin-Inducible Degron (AID) technology enables conditional depletion of targeted proteins. However, the applicability of the AID in vertebrate cells has been limited due to cytotoxicity caused by high auxin concentrations. Here, we establish an improved AID system using an engineered orthogonal auxin-TIR1 pair, which exhibits over 1,000 times stronger binding. With ~1,000-fold less auxin concentration, we achieved to generate the AID-based knockout cells in various human and mouse cell lines in a single transfection.

bioengineering↗