scholarly journals Light-guided intrabodies for on-demand in situ target recognition in human cells

2021 ◽  
Author(s):  
Eike F. Joest ◽  
Christian Winter ◽  
Joshua S. Wesalo ◽  
Alexander Deiters ◽  
Robert Tampé

Nanobodies are ideal to visualize and modulate targets in living cells. We designed a versatile platform for generating photo-conditional intrabodies by genetic code expansion. After illumination, the intrabodies show fast and stable binding.

2022 ◽  
Vol 66 ◽  
pp. 102108
Author(s):  
Kanokpol Aphicho ◽  
Narongyot Kittipanukul ◽  
Chayasith Uttamapinant

2018 ◽  
Author(s):  
Toru Suzuki ◽  
Maki Asami ◽  
Sanjay G. Patel ◽  
Louis Y. P. Luk ◽  
Yu-Hsuan Tsai ◽  
...  

AbstractMultiple applications of genome editing by CRISPR-Cas9 necessitate stringent regulation and Cas9 variants have accordingly been generated whose activity responds to small ligands, temperature or light. However, these approaches are often impracticable, for example in clinical therapeutic genome editing in situ or gene drives in which environmentally-compatible control is paramount. With this in mind, we have developed heritable Cas9-mediated mammalian genome editing that is acutely controlled by the cheap lysine derivative, Lys(Boc) (BOC). Genetic code expansion permitted non-physiological BOC incorporation such that Cas9 (Cas9BOC) was expressed in a full-length, active form in cultured somatic cells only after BOC exposure. Stringently BOC-dependent, heritable editing of transgenic and native genomic loci occurred when Cas9BOC was expressed at the onset of mouse embryonic development from cRNA or Cas9BOC transgenic females. The tightly controlled Cas9 editing system reported here promises to have broad applications and is a first step towards purposed, spatiotemporal gene drive regulation over large geographical ranges.


2019 ◽  
Author(s):  
Yonatan Chemla ◽  
Eden Ozer ◽  
Michael Shaferman ◽  
Ben Zaad ◽  
Rambabu Dandela ◽  
...  

ABSTRACTGenetic code expansion, which enables the site-specific incorporation of unnatural amino acids into proteins, has emerged as a new and powerful tool for protein engineering. Currently, it is mainly utilized inside living cells for a myriad of applications. However, utilization of this technology in a cell-free, reconstituted platform has several advantages over living systems. The common limitations to the employment of these systems are the laborious and complex nature of its preparation and utilization. Herein, we describe a simplified method for the preparation of this system from Escherichia coli cells, which is specifically adapted for the expression of the components needed for cell-free genetic code expansion. In addition, we propose and demonstrate a modular approach to its utilization. By this approach, it is possible to prepare and store different extracts, harboring various translational components, and mix and match them as needed for more than four years retaining its high efficiency. We demonstrate this with the simultaneous incorporation of two different unnatural amino acids into a reporter protein. Finally, we demonstrate the advantage of cell-free systems over living cells for the incorporation of δ-thio-boc-lysine into ubiquitin by using the methanosarcina mazei wild-type pyrrolysyl tRNACUA and tRNA-synthetase pair, which can not be achieved in a living cell.


Author(s):  
Tatsuo Yanagisawa ◽  
Mitsuo Kuratani ◽  
Eiko Seki ◽  
Nobumasa Hino ◽  
Kensaku Sakamoto ◽  
...  

The Analyst ◽  
2021 ◽  
Author(s):  
Yaxin Wang ◽  
Dong-Xia Wang ◽  
Jia-Yi Ma ◽  
Jing Wang ◽  
Yichen Du ◽  
...  

Accurate and specific analysis of adenosine triphosphate (ATP) expression level in living cells can provide valuable information for understanding cell metabolism, physiological activities and pathologic mechanism. Herein, DNA nanolantern-based split...


Amino Acids ◽  
2020 ◽  
Author(s):  
Thomas L. Williams ◽  
Debra J. Iskandar ◽  
Alexander R. Nödling ◽  
Yurong Tan ◽  
Louis Y. P. Luk ◽  
...  

AbstractGenetic code expansion is a powerful technique for site-specific incorporation of an unnatural amino acid into a protein of interest. This technique relies on an orthogonal aminoacyl-tRNA synthetase/tRNA pair and has enabled incorporation of over 100 different unnatural amino acids into ribosomally synthesized proteins in cells. Pyrrolysyl-tRNA synthetase (PylRS) and its cognate tRNA from Methanosarcina species are arguably the most widely used orthogonal pair. Here, we investigated whether beneficial effect in unnatural amino acid incorporation caused by N-terminal mutations in PylRS of one species is transferable to PylRS of another species. It was shown that conserved mutations on the N-terminal domain of MmPylRS improved the unnatural amino acid incorporation efficiency up to five folds. As MbPylRS shares high sequence identity to MmPylRS, and the two homologs are often used interchangeably, we examined incorporation of five unnatural amino acids by four MbPylRS variants at two temperatures. Our results indicate that the beneficial N-terminal mutations in MmPylRS did not improve unnatural amino acid incorporation efficiency by MbPylRS. Knowledge from this work contributes to our understanding of PylRS homologs which are needed to improve the technique of genetic code expansion in the future.


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