Copurification of E. coli RNAase E and PNPase: Evidence for a specific association between two enzymes important in RNA processing and degradation

Carpousis, Agamemnon J.; Houwe, Griet Van; Ehretsmann, C P; Krisch, Henry

doi:10.1016/0092-8674(94)90363-8

Cited by 423 publications

(398 citation statements)

References 27 publications

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“…A panoply of ribonucleases have been identified (Deutscher, 1993), and additional proteins have been reported to be part of a degradosomal complex, e.g. RNase E, PNPase, DnaK, RNA helicase, GroEL and enolase (Carpousis et al, 1994;Miczak et al, 1996;Py et al, 1994;. Even though RNase E cleavage appears to be essential for the decay of bulk RNA (Ono and Kuwano, 1979), its activity is in some cases affected by other ribonucleases: the initial RNase E cleavage in RNA I was shown to be slower in the absence of PNPase (Xu and Cohen, 1995).…”

Section: Discussionmentioning

confidence: 99%

Regulation of plasmid R1 replication: PcnB and RNase E expedite the decay of the antisense RNA, CopA

Söderbom

Binnie

Masters

et al. 1997

Molecular Microbiology

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SummaryThe replication frequency of plasmid R1 is controlled by an unstable antisense RNA, CopA, which, by binding to its complementary target, blocks translation of the replication rate-limiting protein RepA. Since the degree of inhibition is directly correlated with the intracellular concentration of CopA, factors affecting CopA turnover can also alter plasmid copy number. We show here that PcnB (PAP I -a poly(A)polymerase of Escherichia coli ) is such a factor. Previous studies have shown that the copy number of ColE1 is decreased in pcnB mutant strains because the stability of the RNase E processed form of RNAI, the antisense RNA regulator of ColE1 replication, is increased. We find that, analogously, the twofold reduction in R1 copy number caused by a pcnB lesion is associated with a corresponding increase in the stability of the RNase E-generated 3Ј cleavage product of CopA. These results suggest that CopA decay is initiated by RNase E cleavage and that PcnB is involved in the subsequent rapid decay of the 3Ј CopA stem-loop segment. We also find that, as predicted, under conditions in which CopA synthesis is unaffected, pcnB mutation reduces RepA translation and increases CopA stability to the same extent.

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Section: Discussionmentioning

confidence: 99%

Regulation of plasmid R1 replication: PcnB and RNase E expedite the decay of the antisense RNA, CopA

Söderbom

Binnie

Masters

et al. 1997

Molecular Microbiology

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“…The C terminus acts as a scaffold, necessary for protein-protein interactions with polynucleotide phosphorylase (PNPase), an RNA helicase and enolase, a complex that has been called the degradosome (Carpousis et al 1994(Carpousis et al , 1999Py et al 1994Py et al , 1996Miczak et al 1996). Deletions of portions or all of the C terminus are viable, process ribosomal RNA and tRNAs normally, but are slowed for degradation of some messages (Lopez et al 1999;Ow et al 2000; see below).…”

Section: Involvement Of the Degradosomementioning

confidence: 99%

“…The C-ter- minal domain of RNase E, not essential for its catalytic activity, acts as a scaffold for binding of polynucleotide phosphorylase (PNPase), RhlB helicase, and enolase (Carpousis et al 1994(Carpousis et al , 1999Py et al 1994Py et al , 1996Miczak et al 1996). Deletions of this C-terminal domain, although they have little or no effect on the processing of rRNA or tRNAs, significantly slow the degradation of some test substrates (untranslated mRNAs, in particular; Lopez et al 1999;Ow et al 2000;Leroy et al 2002;Ow and Kushner 2002).…”

Section: Degradosome Involvementmentioning

confidence: 99%

Coupled degradation of a small regulatory RNA and its mRNA targets in Escherichia coli

Massé¹,

Escorcia²,

Gottesman³

2003

Genes Dev.

656

836

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RyhB is a small antisense regulatory RNA that is repressed by the Fur repressor and negatively regulates at least six mRNAs encoding Fe-binding or Fe-storage proteins in Escherichia coli. When Fe is limiting, RyhB levels rise, and target mRNAs are rapidly degraded. RyhB is very stable when measured after treatment of cells with the transcription inhibitor rifampicin, but is unstable when overall mRNA transcription continues. We propose that RyhB turnover is coupled to and dependent on pairing with the target mRNAs. Degradation of both mRNA targets and RyhB is dependent on RNase E and is slowed in degradosome mutants. RyhB requires the RNA chaperone Hfq. In the absence of Hfq, RyhB is unstable, even when general transcription is inhibited; degradation is dependent upon RNase E. Hfq and RNase E bind similar sites on the RNA; pairing may allow loss of Hfq and access by RNase E. Two other Hfq-dependent small RNAs, DsrA and OxyS, are also stable when overall transcription is off, and unstable when it is not, suggesting that they, too, are degraded when their target mRNAs are available for pairing. Thus, this large class of regulatory RNAs share an unexpected intrinsic mechanism for shutting off their action.

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“…While the particular RNA structural features that are recognized by the ARRBS are not known, it has been observed that interaction with the ARRBS can alter the higher-order structure of complex RNA substrates . The endonucleolytic activity of a 55 kDa me-dependent protein initially termed RNase K (Lundberg et a/., 1990) is now known to result from an RNase E breakdown product generated by proteolysis occurring either intracellularly or during protein isolation (Mudd and Higgins, 1993;Carpousis et a/., 1994;Lundberg et a/., 1995).…”

Section: The Rne Proteinmentioning

confidence: 99%

RNase E: still a wonderfully mysterious enzyme

Cohen

McDowall

1997

Molecular Microbiology

130

106

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SummaryRibonuclease E (RNase E), which is encoded by an essential Escherichia coli gene known variously as me, ams, and hmp, was discovered initially as an rRNA-processing enzyme but is now known to have a general role in RNA decay. Multiple functions, including the ability t o cleave RNA endonucleolytically in AU-rich single-strand regions, RNA-binding capabilities, and the ability to interact with polynucleotide phosphorylase and other proteins implicated in the processing and degradation of RNA, are encoded by its 1061 amino acid residues. The presence of homologues and functional analogues of the m e gene in a variety of prokaryotic and eukaryotic species suggests that its functions have been highly conserved during evolution. While much has been learned in recent years about the structure and functions of RNase E, there is continuing mystery about possible additional activities and molecular interactions of this enzyme.

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Copurification of E. coli RNAase E and PNPase: Evidence for a specific association between two enzymes important in RNA processing and degradation

Cited by 423 publications

References 27 publications

Regulation of plasmid R1 replication: PcnB and RNase E expedite the decay of the antisense RNA, CopA

Regulation of plasmid R1 replication: PcnB and RNase E expedite the decay of the antisense RNA, CopA

Coupled degradation of a small regulatory RNA and its mRNA targets in Escherichia coli

RNase E: still a wonderfully mysterious enzyme

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