Papers of the month

2012

• February 2012
  • Levine et al. from the lab of Michael Elowitz show how B. subtilis cells can defer sporulation for multiple cell cycles in response to sudden environmental stress. This deferral is controlled by a pulsed positive feedback loop in which phosphorelay kinase expression is activated by pulses of Spo0A phosphorylation.
  • Relevant SubtiWiki pages: Michael Elowitz, Jonathan Dworkin, phosphorelay, sporulation, Spo0A

• • A comment on this paper:

• January 2012
  • Segev et al. from the lab of Sigal Ben-Yehuda demonstrate that ribosomal RNAs are degraded in aging spores by RNase Y. Moreover, the authors show that individual mRNAs experience degradation or accumulation in spores. The study suggests that the kinetics of spore germination depends on the conditions that a spore had experienced before.
  • Relevant SubtiWiki pages: Sigal Ben-Yehuda, RNase Y, germination, RNases

2011

• December 2011
  • Bange et al. from the lab of Irmgard Sinning show how the YlxH protein activates the SRP-GTPase FlhF. The study sheds light on the evolutionary transition from RNA- to protein-driven activation in SRP-GTPases.
  • Relevant SubtiWiki pages: Irmgard Sinning, FlhF, YlxH, signal recognition particle, motility and chemotaxis

• November 2011
  • Locke et al. show how the SigB-dependent general stress response is controlled by signals using stochastic pulse frequency modulation through a compact regulatory architecture.
  • Relevant SubtiWiki pages: Michael Elowitz, SigB, General stress response

Locke JC, Young JW, Fontes M, Hernández Jiménez MJ, Elowitz MB  
Stochastic pulse regulation in bacterial stress response. 
Science. 2011 334:366-369. 
PubMed:21979936

• October 2011
  • Richards et al. identify the nudix hydrolase RppH as the pyrophosphohydrolase that triggers 5'-exonucleolytic degradation of mRNA by RNase J1 in B. subtilis.
  • Relevant SubtiWiki pages: David Bechhofer, Ciaran Condon, RNA processing and degradation, nudix hydrolase, RppH, RNase J1

• September 2011
  • A series of papers deals with RNA processing and degradation in B. subtilis. Three papers establish that RNase Y is the functional equivalent of RNase E from E. coli. Moreover, the role of RNase J1 in endonucleolytic cleavage of the trp leader mRNA is demonstrated.
  • Relevant SubtiWiki pages: David Bechhofer, Rick Lewis, Ulrike Mäder, Harald Putzer, Jörg Stülke, RNases, RNA degradosome, RNase Y, RNase Y targets, RNase J1

Lehnik-Habrink M, Schaffer M, Mäder U, Diethmaier C, Herzberg C, Stülke J  
RNA processing in Bacillus subtilis: identification of targets of the essential RNase Y. 
Mol Microbiol. 2011 81(6): 1459-73. 
PubMed:21815947

• August 2011
  • Chi et al. demonstrate that S-bacillithiolation of the repressor OhrR and of four enzymes of the methionine biosynthesis pathway protects the B. subtilis cell against hypochlorite stress.
  • Relevant SubtiWiki pages: Haike Antelmann, Dörte Becher, Ulrike Mäder, resistance against oxidative and electrophile stress, Spx regulon, CtsR regulon, PerR regulon, OhrR, MetE, YxjG, PpaC, SerA, YphP

• July 2011
  • Domínguez-Escobar et al. from Rut Carballido-Lopez' lab and Garner et al. report that movement of actin-like filaments is driven by the peptidoglycan elongation machinery. Both papers suggest that the MreB-like filaments serve to restrict the mobility of the peptidoglycan synthesizing machinery
    
  • Relevant SubtiWiki pages: Rut Carballido-Lopez, David Rudner, MreB, MreBH, Mbl, MreC, MreD, PbpA, RodA, RodZ, penicillin-binding proteins, cell shape, cell wall synthesis, cell wall biosynthetic complex

• A comment on these papers:

• June 2011
  • Oppenheimer-Shaanan et al. from Sigal Ben-Yehuda's lab report that cyclic di-AMP acts as a secondary messenger that couples DNA integrity with progression of sporulation
    
  • Relevant SubtiWiki pages: Sigal Ben-Yehuda, DisA, GdpP, metabolism of signalling nucleotides, cell division

• May 2011
  • Miles et al. identified the enzyme for the key final step in the biosynthesis of queuosine, a hypermodified base found in the wobble positions of tRNA Asp, Asn, His, and Tyr from bacteria to man
    
  • Relevant SubtiWiki pages: QueG, translation