Past Research

RecA protein assures fidelity of DNA repair and genome stability in Deinococcus radiodurans.

RecA protein assures fidelity of DNA repair and genome stability in Deinococcus radiodurans.
Deinococcus radiodurans is one of the most radiation-resistant organisms known. It can repair hundreds of radiation-induced double-strand DNA breaks without loss of viability. Genome reassembly in heavily irradiated D. radiodurans is considered to be an error-free process since no genome rearrangements were detected after post-irradiation repair. Here, we describe for the first time conditions that frequently cause erroneous chromosomal assemblies.

Protein damage and death by radiation in Escherichia coli and Deinococcus radiodurans.

Protein damage and death by radiation in Escherichia coli and Deinococcus radiodurans.
Deinococcus radiodurans is among a small number of bacterial species that are extremely resistant to ionizing radiation, UV light, toxic chemicals, and desiccation. We measured proteome oxidation (i.e., protein carbonylation, PC) in D. radiodurans as well as in standard and evolved resistant strains of Escherichia coli exposed to ionizing radiation or UVC light and found a consistent correlation with cell killing. The unique quantitative relationship between incurred PC and cell death holds over the entire range of killing for all tested bacteria and for both lethal agents, meaning that both bacterial species are equally sensitive to PC.

Unstructured hydrophilic sequences in prokaryotic proteomes correlate with dehydration tolerance and host association.

Unstructured hydrophilic sequences in prokaryotic proteomes correlate with dehydration tolerance and host association.
Here, we explore possible hallmarks of prokaryotic desiccation tolerance in their proteomes. The content of unstructured, low complexity (LC) regions was analyzed in a total of 460 bacterial and archaeal proteomes. It appears that species endowed with proteomes abundant in unstructured hydrophilic LC regions are desiccation-tolerant or sporulating bacteria, halophilic archaea and bacteria, or host-associated species.

Read all Past Researches

Greatest quotes

Philosophers say a great deal about what is absolutely necessary for science, and it is always, so far as one can see, rather naive, and probably wrong.

- Richard Feynman -

No flash player!

It looks like you don't have flash player installed. Click here to go to Macromedia download page.

Protein damage and death by radiation in Escherichia coli and Deinococcus radiodurans.

Proc Natl Acad Sci U S A. 2010 Aug 10;107(32):14373-7. Epub 2010 Jul 26.

 

Source

Institut National de la Santé et de la Recherche Médicale Unit 571, University Paris-Descartes Medical School, 75751 Paris Cedex 15, France.

Abstract

Deinococcus radiodurans is among a small number of bacterial species that are extremely resistant to ionizing radiation, UV light, toxic chemicals, and desiccation. We measured proteome oxidation (i.e., protein carbonylation, PC) in D. radiodurans as well as in standard and evolved resistant strains of Escherichia coli exposed to ionizing radiation or UVC light and found a consistent correlation with cell killing. The unique quantitative relationship between incurred PC and cell death holds over the entire range of killing for all tested bacteria and for both lethal agents, meaning that both bacterial species are equally sensitive to PC. We show that the extraordinary robustness of D. radiodurans depends on efficient proteome protection (but not DNA protection) against constitutive and radiation-induced PC consisting of low molecular weight cytosolic compounds. Remarkably, experimental evolution of resistance to ionizing radiation in E. coli coevolves with protection against PC. The decline in biosynthetic efficacy of the cellular proteome, as measured by the loss of reproduction of undamaged bacteriophage lambda in irradiated standard and evolved ionizing radiation-resistant E. coli, correlates with radiation-induced oxidative damage to host cells and their sensitivity to ionizing radiation. This correlation suggests that cell death by radiation is caused primarily by oxidative damage with consequential loss of maintenance activities including DNA repair.

 

 

click to read the article

 

 

 

 

 

 

 

 

 

 

 

 

 

Homepage Homepage English English Fran├žais Fran├žais Hrvatski Hrvatski Facebook Facebook

Miroslav Radman - Molecular Biology and Genetics Scientist