<i><scp>B</scp>acillus subtilis</i> serine/threonine protein kinase <scp>YabT</scp> is involved in spore development via phosphorylation of a bacterial recombinase

Bidnenko, Vladimir; Shi, Lei; Kobir, Ahasanul; Ventroux, Magali; Pigeonneau, Nathalie; Henry, Céline; Trubuil, Alain; Noirot‐Gros, Marie‐Françoise; Mijaković, Ivan

doi:10.1111/mmi.12233

Cited by 43 publications

(66 citation statements)

References 55 publications

(90 reference statements)

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“…1C). This observation is consistent with the involvement of YabT in spore development (14) and suggests a possible regulatory role for this kinase in the progressive metabolic quiescence of the forespore.…”

Section: Resultssupporting

confidence: 88%

Protein synthesis during cellular quiescence is inhibited by phosphorylation of a translational elongation factor

Pereira

Gonzalez

Dworkin

2015

Proc. Natl. Acad. Sci. U.S.A.

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In nature, most organisms experience conditions that are suboptimal for growth. To survive, cells must fine-tune energy-demanding metabolic processes in response to nutrient availability. Here, we describe a novel mechanism by which protein synthesis in starved cells is down-regulated by phosphorylation of the universally conserved elongation factor Tu (EF-Tu). Phosphorylation impairs the essential GTPase activity of EF-Tu, thereby preventing its release from the ribosome. As a consequence, phosphorylated EF-Tu has a dominant-negative effect in elongation, resulting in the overall inhibition of protein synthesis. Importantly, this mechanism allows a quick and robust regulation of one of the most abundant cellular proteins. Given that the threonine that serves as the primary site of phosphorylation is conserved in all translational GTPases from bacteria to humans, this mechanism may have important implications for growth-rate control in phylogenetically diverse organisms.A daptation to nutrient availability is a fundamental cellular process. From unicellular prokaryotes to complex multicellular organisms, cells sense and adjust their metabolism to respond to variations in nutrient levels. Protein synthesis is one of the most energy-intensive cellular processes, and both the initiation and elongation stages of translation are down-regulated in response to nutrient limitation (1). Proteins that mediate translation, such as the essential and universally conserved GTPase Elongation factor Tu (EF-Tu), are observed in the phosphoproteomes of diverse organisms (2), suggesting that they are subject to regulatory phosphorylation. However, EF-Tu is the most abundant protein in bacteria, present at ∼100,000 copies per cell of growing Escherichia coli (3), but less than 10% of the EF-Tu molecules are phosphorylated (4). Thus, a key question is how this relatively small fraction of phosphorylated EF-Tu can cause a down-regulation of protein synthesis.GTP-bound EF-Tu binds and delivers an aminoacyl-tRNA (aa-tRNA) molecule to the translating ribosome (3). Upon formation of a correctly base-paired mRNA codon-aa-tRNA anticodon interaction, the ribosome activates the GTPase activity of EF-Tu, followed by accommodation of the aa-tRNA into the ribosomal aa-tRNA binding (A) site, and release of the inactive GDP-bound EF-Tu from the ribosome. EF-Tu belongs to the GTPase superfamily which comprises molecular switches that share a core catalytic domain and mechanism but have evolved to perform diverse roles in many cellular processes (5). Central to their function is the hydrolysis of GTP, which controls the switch between the ON, GTP-bound, and the OFF, GDP-bound, states. Hydrolysis of GTP is followed by large conformational changes in two flexible regions known as "switch I" and "switch II." These regions are composed of highly conserved motifs that surround and contact the nucleotide and are involved in interactions with both exchange factors and effectors that regulate GTPase function.GTPases also can be regulated by direct inhibiti...

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Section: Resultssupporting

confidence: 88%

Protein synthesis during cellular quiescence is inhibited by phosphorylation of a translational elongation factor

Pereira

Gonzalez

Dworkin

2015

Proc. Natl. Acad. Sci. U.S.A.

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“…Phosphorylation of B. subtilis RecA at serine 2 by the YabT Hanks type serine/threonine kinase modulates spore development (17). B. subtilis also encodes a tyrosine kinase that phosphorylates a tyrosine in RecA (29).…”

Section: Discussionmentioning

confidence: 99%

“…Although involvement of Ser/Thr/Tyr phosphorylation of DNA repair proteins in DNA repair and cell cycle regulation is widespread in eukaryotes, it is unusual in bacteria. In Bacillus subtilis, the tyrosine phosphorylation of SSB enhances its affinity for ssDNA (16), and phosphorylation of B. subtilis recombinase by a DNA damage-inducible serine/threonine protein kinase was recently reported (17). We characterized RqkA, a eukaryotic type DNA damage-responsive Ser/Thr protein kinase (eSTPK) in D. radiodurans and demonstrated its involvement in ␥ radiation resistance and DSB repair (18).…”

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confidence: 96%

Phosphorylation of Deinococcus radiodurans RecA Regulates Its Activity and May Contribute to Radioresistance

Rajpurohit

Bihani

Waldor

et al. 2016

Journal of Biological Chemistry

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Deinococcus radiodurans has a remarkable capacity to survive exposure to extreme levels of radiation that cause hundreds of DNA double strand breaks (DSBs). DSB repair in this bacterium depends on its recombinase A protein (DrRecA). DrRecA plays a pivotal role in both extended synthesis-dependent strand annealing and slow crossover events of DSB repair during the organism's recovery from DNA damage. The mechanisms that control DrRecA activity during the D. radiodurans response to ␥ radiation exposure are unknown. Here, we show that DrRecA undergoes phosphorylation at Tyr-77 and Thr-318 by a DNA damage-responsive serine threonine/tyrosine protein kinase (RqkA). Phosphorylation modifies the activity of DrRecA in several ways, including increasing its affinity for dsDNA and its preference for dATP over ATP. Strand exchange reactions catalyzed by phosphorylated versus unphosphorylated DrRecA also differ. In silico analysis of DrRecA structure support the idea that phosphorylation can modulate crucial functions of this protein. Collectively, our findings suggest that phosphorylation of DrRecA enables the recombinase to selectively use abundant dsDNA substrate present during post-irradiation recovery for efficient DSB repair, thereby promoting the extraordinary radioresistance of D. radiodurans.Deinococcus radiodurans has a remarkable capacity to survive extreme doses of radiations and other DNA-damaging agents. Studies aimed at unraveling the molecular bases for these unusual properties have revealed that D. radiodurans encodes mechanisms for highly efficient DNA double strand break (DSB) 2 repair and oxidative stress management (1-3). DSB repair in this Gram-positive bacterium is accomplished in two phases during post-irradiation recovery (PIR); phase I is dominated by extended synthesis-dependent strand annealing (ESDSA) processes, whereas phase II involves slow crossover events in homologous recombination leading to the repair and re-establishment of the multipartite D. radiodurans genome structure (4). Despite the fact that the two phases of PIR have DNA substrates of different structures and topologies, D. radiodurans RecA (DrRecA) is required throughout DSB repair during PIR (5). Biochemical characterization of recombinant DrRecA revealed that it can form a filament on singlestranded DNA (ssDNA), exhibit co-protease activity, and utilize ATP or dATP for its energy requirements, akin to other bacterial RecA proteins (6), but it also has unusual properties. In contrast to most bacterial RecA proteins, DrRecA promotes inverse strand exchange reactions (7). Also, DrRecA promotes DNA degradation during the early phase of ESDSA repair (5), which is opposite to the function observed with Escherichia coli RecA. Transcription of DrRecA is induced in response to ␥ radiation (8, 9). However, the mechanisms by which ␥ radiation induces DrRecA expression are unusual. Inactivation of both D. radiodurans lexA genes does not attenuate ␥ radiation induction of DrRecA expression (10, 11). Thus, in contrast to many bacteria, LexA...

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“…Since phosphorylation inhibits DNA binding, phosphorylation of HupB specifically during exponential phase would limit its interaction with DNA and ensure that its effects are limited to stationary phase. In addition, the B. subtilis eSTK YabT phosphorylates the DNA recombinase RecA on Ser-2, with an effect on RecA foci formation [56]. …”

Section: Modification Of Transcription Factorsmentioning

confidence: 99%

Ser/Thr phosphorylation as a regulatory mechanism in bacteria

Dworkin

2015

Current Opinion in Microbiology

118

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This review will discuss some recent work describing the role of Ser/Thr phosphorylation as a post-translational mechanism of regulation in bacteria. I will discuss the interaction between bacterial eukaryotic-like Ser/Thr kinases (eSTKs) and two-component systems as well as hints as to physiological function of eSTKs and their cognate eukaryotic-like phosphatases (eSTPs). In particular, I will highlight the role of eSTKs and eSTPs in the regulation of peptidoglycan metabolism and protein synthesis. In addition, I will discuss how data from phosphoproteomic surveys suggests that Ser/Thr phosphorylation plays a much more significant physiological role than would be predicted simply based on in vivo and in vitro analyses of individual kinases.

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Bacillus subtilis serine/threonine protein kinase YabT is involved in spore development via phosphorylation of a bacterial recombinase

Cited by 43 publications

References 55 publications

Protein synthesis during cellular quiescence is inhibited by phosphorylation of a translational elongation factor

Protein synthesis during cellular quiescence is inhibited by phosphorylation of a translational elongation factor

Phosphorylation of Deinococcus radiodurans RecA Regulates Its Activity and May Contribute to Radioresistance

Ser/Thr phosphorylation as a regulatory mechanism in bacteria

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