scholarly journals AirID, a novel proximity biotinylation enzyme, for analysis of protein–protein interactions

eLife ◽  
2020 ◽  
Vol 9 ◽  
Author(s):  
Kohki Kido ◽  
Satoshi Yamanaka ◽  
Shogo Nakano ◽  
Kou Motani ◽  
Souta Shinohara ◽  
...  

Proximity biotinylation based on Escherichia coli BirA enzymes such as BioID (BirA*) and TurboID is a key technology for identifying proteins that interact with a target protein in a cell or organism. However, there have been some improvements in the enzymes that are used for that purpose. Here, we demonstrate a novel BirA enzyme, AirID (ancestral BirA for proximity-dependent biotin identification), which was designed de novo using an ancestral enzyme reconstruction algorithm and metagenome data. AirID-fusion proteins such as AirID-p53 or AirID-IκBα indicated biotinylation of MDM2 or RelA, respectively, in vitro and in cells, respectively. AirID-CRBN showed the pomalidomide-dependent biotinylation of IKZF1 and SALL4 in vitro. AirID-CRBN biotinylated the endogenous CUL4 and RBX1 in the CRL4CRBN complex based on the streptavidin pull-down assay. LC-MS/MS analysis of cells that were stably expressing AirID-IκBα showed top-level biotinylation of RelA proteins. These results indicate that AirID is a novel enzyme for analyzing protein–protein interactions.

2020 ◽  
Author(s):  
Sharon Spizzichino ◽  
Dalila Boi ◽  
Giovanna Boumis ◽  
Roberta Lucchi ◽  
Francesca R. Liberati ◽  
...  

ABSTRACTDe novo thymidylate synthesis is a crucial pathway for normal and cancer cells. Deoxythymidine monophosphate (dTMP) is synthesized by the combined action of three enzymes: thymidylate synthase (TYMS), serine hydroxymethyltransferase (SHMT) and dihydrofolate reductase (DHFR), targets of widely used chemotherapeutics such as antifolates and 5-fluorouracil. These proteins translocate to the nucleus after SUMOylation and are suggested to assemble in this compartment into the thymidylate synthesis complex (dTMP-SC). We report the intracellular dynamics of the complex in lung cancer cells by in situ proximity ligation assay, showing that it is also detected in the cytoplasm. We have successfully assembled the dTMP synthesis complex in vitro, employing tetrameric SHMT1 and a bifunctional chimeric enzyme comprising human TYMS and DHFR. We show that the SHMT1 tetrameric state is required for efficient complex assembly, indicating that this aggregation state is evolutionary selected in eukaryotes to optimize protein-protein interactions. Lastly, our results on the activity of the complete thymidylate cycle in vitro, provide a useful tool to develop drugs targeting the entire complex instead of the individual components.


2015 ◽  
Vol 370 (1679) ◽  
pp. 20150031 ◽  
Author(s):  
Alexander J. F. Egan ◽  
Jacob Biboy ◽  
Inge van't Veer ◽  
Eefjan Breukink ◽  
Waldemar Vollmer

Peptidoglycan (PG) is an essential component in the cell wall of nearly all bacteria, forming a continuous, mesh-like structure, called the sacculus, around the cytoplasmic membrane to protect the cell from bursting by its turgor. Although PG synthases, the penicillin-binding proteins (PBPs), have been studied for 70 years, useful in vitro assays for measuring their activities were established only recently, and these provided the first insights into the regulation of these enzymes. Here, we review the current knowledge on the glycosyltransferase and transpeptidase activities of PG synthases. We provide new data showing that the bifunctional PBP1A and PBP1B from Escherichia coli are active upon reconstitution into the membrane environment of proteoliposomes, and that these enzymes also exhibit DD-carboxypeptidase activity in certain conditions. Both novel features are relevant for their functioning within the cell. We also review recent data on the impact of protein–protein interactions and other factors on the activities of PBPs. As an example, we demonstrate a synergistic effect of multiple protein–protein interactions on the glycosyltransferase activity of PBP1B, by its cognate lipoprotein activator LpoB and the essential cell division protein FtsN.


2003 ◽  
Vol 185 (8) ◽  
pp. 2393-2401 ◽  
Author(s):  
Yi-Ying Lee ◽  
Chiung-Fang Chang ◽  
Chueh-Ling Kuo ◽  
Meng-Ching Chen ◽  
Chien Hung Yu ◽  
...  

ABSTRACT The Escherichia coli ClpYQ (HslUV) is an ATP-dependent protease that consists of an ATPase large subunit with homology to other Clp family ATPases and a peptidase small subunit related to the proteasomal β-subunits of eukaryotes. Six identical subunits of both ClpY and ClpQ self-assemble into an oligomeric ring, and two rings of each subunit, two ClpQ rings surrounded by single ClpY rings, form a dumbbell shape complex. The ClpYQ protease degrades the cell division inhibitor, SulA, and a positive regulator of capsule transcription, RcsA, as well as RpoH, a heat shock sigma transcription factor. Using the yeast-two hybrid system, we explored the in vivo protein-protein interactions of the individual subunits of the ClpYQ protease involved in self-oligomerization, as well as in recognition of specific substrates. Interactions were detected with ClpQ/ClpQ, ClpQ/ClpY, and ClpY/SulA. No interactions were observed in experiments with ClpY/ClpY, ClpQ/RcsA, and ClpQ/SulA. However, ClpY, lacking domain I (ClpYΔI) was able to interact with itself and with intact ClpY. The C-terminal region of ClpY is important for interaction with other ClpY subunits. The previously defined PDZ-like domains at the C terminus of ClpY, including both D1 and D2, were determined to be indispensable for substrate binding. Various deletion and random point mutants of SulA were also made to verify significant interactions with ClpY. Thus, we demonstrated in vivo hetero- and homointeractions of ClpQ and ClpY molecules, as well as a direct association between ClpY and substrate SulA, thereby supporting previous in vitro biochemical findings.


2021 ◽  
Vol 12 (14) ◽  
pp. 5164-5170
Author(s):  
Salvador Guardiola ◽  
Monica Varese ◽  
Xavier Roig ◽  
Macarena Sánchez-Navarro ◽  
Jesús García ◽  
...  

In silico design of heterochiral cyclic peptides that bind to a specific surface patch on the target protein (PD-1, in this case) and disrupt protein–protein interactions.


2021 ◽  
Vol 7 (15) ◽  
pp. eabg1950
Author(s):  
Nicolas Bery ◽  
Carole J.R. Bataille ◽  
Angela Russell ◽  
Angela Hayes ◽  
Florence Raynaud ◽  
...  

Intracellular antibodies are tools that can be used directly for target validation by interfering with properties like protein-protein interactions. An alternative use of intracellular antibodies in drug discovery is developing small-molecule surrogates using antibody-derived (Abd) technology. We previously used this strategy with an in vitro competitive surface plasmon resonance method that relied on high-affinity antibody fragments to obtain RAS-binding compounds. We now describe a novel implementation of the Abd method with a cell-based intracellular antibody–guided screening method that we have applied to the chromosomal translocation protein LMO2. We have identified a chemical series of anti-LMO2 Abd compounds that bind at the same LMO2 location as the inhibitory anti-LMO2 intracellular antibody combining site. Intracellular antibodies could therefore be used in cell-based screens to identify chemical surrogates of their binding sites and potentially be applied to any challenging proteins, such as transcription factors that have been considered undruggable.


2021 ◽  
Vol 118 (17) ◽  
pp. e2021569118
Author(s):  
Danny D. Sahtoe ◽  
Adrian Coscia ◽  
Nur Mustafaoglu ◽  
Lauren M. Miller ◽  
Daniel Olal ◽  
...  

The de novo design of polar protein–protein interactions is challenging because of the thermodynamic cost of stripping water away from the polar groups. Here, we describe a general approach for designing proteins which complement exposed polar backbone groups at the edge of beta sheets with geometrically matched beta strands. We used this approach to computationally design small proteins that bind to an exposed beta sheet on the human transferrin receptor (hTfR), which shuttles interacting proteins across the blood–brain barrier (BBB), opening up avenues for drug delivery into the brain. We describe a design which binds hTfR with a 20 nM Kd, is hyperstable, and crosses an in vitro microfluidic organ-on-a-chip model of the human BBB. Our design approach provides a general strategy for creating binders to protein targets with exposed surface beta edge strands.


2013 ◽  
Vol 3 (5) ◽  
pp. 20130018 ◽  
Author(s):  
E. Sierecki ◽  
N. Giles ◽  
M. Polinkovsky ◽  
M. Moustaqil ◽  
K. Alexandrov ◽  
...  

Protein–protein interactions are highly desirable targets in drug discovery, yet only a fraction of drugs act as binding inhibitors. Here, we review the different technologies used to find and validate protein–protein interactions. We then discuss how the novel combination of cell-free protein expression, AlphaScreen and single-molecule fluorescence spectroscopy can be used to rapidly map protein interaction networks, determine the architecture of protein complexes, and find new targets for drug discovery.


2003 ◽  
Vol 185 (18) ◽  
pp. 5491-5499 ◽  
Author(s):  
Sun Nyunt Wai ◽  
Marie Westermark ◽  
Jan Oscarsson ◽  
Jana Jass ◽  
Elke Maier ◽  
...  

ABSTRACT We report studies of the subcellular localization of the ClyA cytotoxic protein and of mutations causing defective translocation to the periplasm in Escherichia coli. The ability of ClyA to translocate to the periplasm was abolished in deletion mutants lacking the last 23 or 11 amino acid residues of the C-terminal region. A naturally occurring ClyA variant lacking four residues (183 to 186) in a hydrophobic subdomain was retained mainly in the cytosolic fraction. These mutant proteins displayed an inhibiting effect on the expression of the hemolytic phenotype of wild-type ClyA. Studies in vitro with purified mutant ClyA proteins revealed that they were defective in formation of pore assemblies and that their activity in hemolysis assays and in single-channel conductance tests was at least 10-fold lower than that of the wild-type ClyA. Tests with combinations of the purified proteins indicated that mutant and wild-type ClyA interacted and that formation of heteromeric assemblies affected the pore-forming activity of the wild-type protein. The observed protein-protein interactions were consistent with, and provided a molecular explanation for, the dominant negative feature of the mutant ClyA variants.


2009 ◽  
Vol 390 (1) ◽  
Author(s):  
Corinna Ottmann ◽  
Michael Weyand ◽  
Alexander Wolf ◽  
Jürgen Kuhlmann ◽  
Christian Ottmann

Abstract Bimolecular fluorescence complementation (BiFC) using yellow fluorescent protein (YFP) is a widely employed method to study protein-protein interactions in cells. As yet, this technique has not been used in vitro. To evaluate a possible application of BiFC in vitro, we constructed a ‘superfolder split YFP’ system where 15 mutations enhance expression of the fusion proteins in Escherichia coli and enable a native purification due to improved solubility. Here, we present the crystal structure of ‘superfolder YFP’, providing the structural basis for the enhanced folding and stability characteristics. Complementation between the two non-fluorescent YFP fragments fused to HRas and Raf1RBD or to 14-3-3 and PMA2-CT52 resulted in the constitution of the functional fluorophore. The in vivo BiFC with these protein interaction pairs was demonstrated in eukaryotic cell lines as well. Here, we present for the first time BiFC in vitro studies with natively purified superfolder YFP fusion proteins and show the potential and drawbacks of this method for analyzing protein-protein interactions.


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