TY - JOUR
T1 - Studies on Escherichia coli HflKC suggest the presence of an unidentified factor that influences the lysis-lysogeny switch
AU - Bandyopadhyay, Kaustav
AU - Parua, Pabitra K.
AU - Datta, Ajit B.
AU - Parrack, Pradeep
N1 - Funding Information:
We thank S. Adhya (NIH, Bethesda) for lcIII67and for his comments on the manuscript, K. Ito and Y. Akiyama (Kyoto University) for E. coli AK990 strain, S. K. Dasgupta (Bose Institute) for the plasmid pSD5b and K. Shearwin (University of Adelaide) for anti-CII antibody. This work was funded by Institutional Project 5 (Microbial Genomics) of Bose Institute. KB was supported by CSIR, India (F. No. 9/15 (302)/2004-EMR-I).
PY - 2011
Y1 - 2011
N2 - Background: The lysis-lysogeny decision in the temperate coliphage γ is influenced by a number of phage proteins (CII and CIII) as well as host factors, viz. Escherichia coli HflB, HflKC and HflD. Prominent among these are the transcription factor CII and HflB, an ATP-dependent protease that degrades CII. Stabilization of CII promotes lysogeny, while its destabilization induces the lytic mode of development. All other factors that influence the lytic/lysogenic decision are known to act by their effects on the stability of CII. Deletion of hflKC has no effect on the stability of CII. However, when γ infects ΔhflKC cells, turbid plaques are produced, indicating stabilization of CII under these conditions. Results: We find that CII is stabilized in ΔhflKC cells even without infection by γ, if CIII is present. Nevertheless, we also obtained turbid plaques when a ΔhflKC host was infected by a cIII-defective phage (ΔcIII67). This observation raises a fundamental question: does lysogeny necessarily correlate with the stabilization of CII? Our experiments indicate that CII is indeed stabilized under these conditions, implying that stabilization of CII is possible in hflKC cells even in the absence of CIII, leading to lysogeny. Conclusion: We propose that a yet unidentified CII-stabilizing factor in γ may influence the lysis-lysogeny decision in ΔhflKC cells.
AB - Background: The lysis-lysogeny decision in the temperate coliphage γ is influenced by a number of phage proteins (CII and CIII) as well as host factors, viz. Escherichia coli HflB, HflKC and HflD. Prominent among these are the transcription factor CII and HflB, an ATP-dependent protease that degrades CII. Stabilization of CII promotes lysogeny, while its destabilization induces the lytic mode of development. All other factors that influence the lytic/lysogenic decision are known to act by their effects on the stability of CII. Deletion of hflKC has no effect on the stability of CII. However, when γ infects ΔhflKC cells, turbid plaques are produced, indicating stabilization of CII under these conditions. Results: We find that CII is stabilized in ΔhflKC cells even without infection by γ, if CIII is present. Nevertheless, we also obtained turbid plaques when a ΔhflKC host was infected by a cIII-defective phage (ΔcIII67). This observation raises a fundamental question: does lysogeny necessarily correlate with the stabilization of CII? Our experiments indicate that CII is indeed stabilized under these conditions, implying that stabilization of CII is possible in hflKC cells even in the absence of CIII, leading to lysogeny. Conclusion: We propose that a yet unidentified CII-stabilizing factor in γ may influence the lysis-lysogeny decision in ΔhflKC cells.
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U2 - 10.1186/1471-2180-11-34
DO - 10.1186/1471-2180-11-34
M3 - Article
C2 - 21324212
AN - SCOPUS:79951584466
SN - 1471-2180
VL - 11
JO - BMC Microbiology
JF - BMC Microbiology
M1 - 34
ER -