scholarly journals Faculty Opinions recommendation of Redox controls RecA protein activity via reversible oxidation of its methionine residues.

2021 ◽  
Author(s):  
Justin Courcelle
Keyword(s):  
Reca Protein ◽  
Protein Activity ◽  
Methionine Residues

scholarly journals Redox controls RecA protein activity via reversible oxidation of its methionine residues

eLife ◽  
2021 ◽  
Vol 10 ◽  
Author(s):  
Camille Henry ◽  
Laurent Loiseau ◽  
Alexandra Vergnes ◽  
Didier Vertommen ◽  
Angela Mérida-Floriano ◽  
...  
Keyword(s):  
Dna Recombination ◽  
Reca Protein ◽  
Methionine Sulfoxide ◽  
Mass Spectrometry Analysis ◽  
Loss Of Function ◽  
Protein Activity ◽  
Spectrometry Analysis ◽  
Methionine Sulfoxide Reductases ◽  
Methionine Residues ◽  
Biochemical Analyses

Reactive oxygen species (ROS) cause damage to DNA and proteins. Here we report that the RecA recombinase is itself oxidized by ROS. Genetic and biochemical analyses revealed that oxidation of RecA altered its DNA repair and DNA recombination activities. Mass spectrometry analysis showed that exposure to ROS converted 4 out of 9 Met residues of RecA to methionine sulfoxide. Mimicking oxidation of Met35 by changing it for Gln caused complete loss of function whereas mimicking oxidation of Met164 resulted in constitutive SOS activation and loss of recombination activity. Yet, all ROS-induced alterations of RecA activity were suppressed by methionine sulfoxide reductases MsrA and MsrB. These findings indicate that under oxidative stress, MsrA/B is needed for RecA homeostasis control. The implication is that, besides damaging DNA structure directly, ROS prevent repair of DNA damage by hampering RecA activity.

scholarly journals An Activity-Based Methionine Bioconjugation Approach to Developing Proximity-Activated Imaging Reporters

2019 ◽  
Author(s):  
Jun Ohata ◽  
Lakshmi Krishnamoorthy ◽  
Monica Gonzalez ◽  
Tong Xiao ◽  
Diana Iovan ◽  
...  
Keyword(s):  
Protein Detection ◽  
Specific Protein ◽  
Protein Activity ◽  
Protein Targets ◽  
Sensing Platform ◽  
Starting Point ◽  
Methionine Residues ◽  
Endogenous Activity

Chemical probes that report on protein activity, rather than protein abundance, with spatial and temporal resolution can enable studies of their native function in biological contexts as well as provide opportunities for developing new types of biochemical reporters. Here we present a sensing platform, termed proximity-activated imaging reporter (PAIR), which combines activity-based methionine bioconjugation and antibody labeling with proximity-dependent oligonucleotide-based amplification to monitor dynamic changes of a given analyte in cells and animals through context-dependent methionine labeling of specific protein targets. We establish this PAIR method to develop sensors for imaging reactive oxygen species (ROS) and calcium ions through oxaziridine-directed labeling of reactive methionine residues on β-actin and calmodulin (CaM), respectively, where the extent of methionine bioconjugation on these protein targets can serve as an indicator of oxidative stress or calcium status. In particular, application of PAIR to activity-based CaM detection provides a method for imaging integrated calcium activity in both in vitro cell and in vivo zebrafish models. By relying on native protein biochemistry, PAIR enables redox and metal imaging without introduction of external small-molecules or genetically encoded indicators that can potentially buffer the natural/existing pools. This approach can be potentially generalized to target a broader range of analytes by pairing appropriate activity-based protein probes with protein detection reagents in a proximity-driven manner, providing a starting point not only for designing new sensors but also for monitoring endogenous activity of specific protein targets in biological specimens with spatial and temporal fidelity.

scholarly journals An Activity-Based Methionine Bioconjugation Approach to Developing Proximity-Activated Imaging Reporters

2019 ◽  
Author(s):  
Jun Ohata ◽  
Lakshmi Krishnamoorthy ◽  
Monica Gonzalez ◽  
Tong Xiao ◽  
Diana Iovan ◽  
...  
Keyword(s):  
Protein Detection ◽  
Specific Protein ◽  
Protein Activity ◽  
Protein Targets ◽  
Sensing Platform ◽  
Starting Point ◽  
Methionine Residues ◽  
Endogenous Activity

Chemical probes that report on protein activity, rather than protein abundance, with spatial and temporal resolution can enable studies of their native function in biological contexts as well as provide opportunities for developing new types of biochemical reporters. Here we present a sensing platform, termed proximity-activated imaging reporter (PAIR), which combines activity-based methionine bioconjugation and antibody labeling with proximity-dependent oligonucleotide-based amplification to monitor dynamic changes of a given analyte in cells and animals through context-dependent methionine labeling of specific protein targets. We establish this PAIR method to develop sensors for imaging reactive oxygen species (ROS) and calcium ions through oxaziridine-directed labeling of reactive methionine residues on β-actin and calmodulin (CaM), respectively, where the extent of methionine bioconjugation on these protein targets can serve as an indicator of oxidative stress or calcium status. In particular, application of PAIR to activity-based CaM detection provides a method for imaging integrated calcium activity in both in vitro cell and in vivo zebrafish models. By relying on native protein biochemistry, PAIR enables redox and metal imaging without introduction of external small-molecules or genetically encoded indicators that can potentially buffer the natural/existing pools. This approach can be potentially generalized to target a broader range of analytes by pairing appropriate activity-based protein probes with protein detection reagents in a proximity-driven manner, providing a starting point not only for designing new sensors but also for monitoring endogenous activity of specific protein targets in biological specimens with spatial and temporal fidelity.

Restoration of RecA protein activity by genetic complementation

1984 ◽  
Vol 195 (1-2) ◽  
pp. 83-89 ◽  
Author(s):  
J. E. Rebollo ◽  
P. L. Moreau ◽  
M. Blanco ◽  
R. Devoret
Keyword(s):  
Reca Protein ◽  
Genetic Complementation ◽  
Protein Activity

Electron Microscopy and image analysis of nucleo-protein complexes

1994 ◽  
Vol 52 ◽  
pp. 88-89
Author(s):  
E. H. Egelman ◽  
X. Yu
Keyword(s):  
Electron Microscopy ◽  
Image Analysis ◽  
Normal Cell ◽  
Genetic Recombination ◽  
Protein Complexes ◽  
Chromosomal Rearrangements ◽  
Reca Protein ◽  
E Coli ◽  
Helical Polymer ◽  
Specific Protease

The RecA protein of E. coli has been shown to mediate genetic recombination, regulate its own synthesis, control the expression of other genes, act as a specific protease, form a helical polymer and have an ATPase activity, among other observed properties. The unusual filament formed by the RecA protein on DNA has not previously been shown to exist outside of bacteria. Within this filament, the 36 Å pitch of B-form DNA is extended to about 95 Å, the pitch of the RecA helix. We have now establishedthat similar nucleo-protein complexes are formed by bacteriophage and yeast proteins, and availableevidence suggests that this structure is universal across all of biology, including humans. Thus, understanding the function of the RecA protein will reveal basic mechanisms, in existence inall organisms, that are at the foundation of general genetic recombination and repair.Recombination at this moment is assuming an importance far greater than just pure biology. The association between chromosomal rearrangements and neoplasms has become stronger and stronger, and these rearrangements are most likely products of the recombinatory apparatus of the normal cell. Further, damage to DNA appears to be a major cause of cancer.

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