A recombinant foot-and-mouth disease virus antigen inhibits DNA replication and triggers the SOS response in

Abstract

The 3D gene of foot-and-mouth disease virus encodes the viral RNA dependent RNA polymerase, also called virus infection associated (VIA) antigen, which is the most important serological marker of virus infection. This 3D gene from a serotype C1 virus has been cloned and overexpressed in Escherichia coli under the control of the strong lambda lytic promoters. The resulting 51 kDa recombinant protein has been shown to be immunoreactive with sera from infected animals. After induction of gene expression, an immediate and dramatic arrest of cell DNA synthesis occurs, similar to that produced by genotoxic doses of the drug mitomycin C. This effect does not occur during the production of either a truncated VIA antigen or other related and non-related viral proteins. The inhibition of DNA replication results in a subsequent induction of the host SOS DNA-repair response and in an increase of the mutation frequency in the surviving cells.

Heat-inactivation of plasmid-encoded CI857 repressor induces gene expression from Ind−lambda prophage in recombinantEscherichia coli

“…The time‐dependent evolution of the reporter β‐galactosidase activity in the induced recombinant culture (Fig. 1A) was comparable to previously published results on the induction of the SOS gene upon temperature up‐shift in temperature‐inducible expression systems [15,25]. However, sulA gene expression is also observed in the strain harboring the parental vector pCYTEXP1 without any cloned gene, suggesting that the biosynthesis of a complete protein is not required for the activation of the sulA transcription.…”

“…Considering these results, it could not be excluded that the previously reported transcription of the sulA :: lacZ fusion in response to temperature up‐shift of GC4581 carrying CI857‐controlled, lambda‐based expression vectors [15] could be enhanced by an extended transcription of lambda lytic genes. The possibility of an unspecific transcription of the reporter gene does not apply to E. coli GE864, in which SOS transcription has also been observed during thermal induction of a CI857‐repressed recombinant gene [25]. Having a different origin and lacking any lambda prophage [17], this strain does not show detectable cell lysis upon thermal up‐shift (Fig.…”

Heat-inactivation of plasmid-encoded CI857 repressor induces gene expression from Ind− lambda prophage in recombinant Escherichia coli

“…The time-dependent evolution of the reporter L-galactosidase activity in the induced recombinant culture (Fig. 1A) was comparable to previously published results on the induction of the SOS gene upon temperature up-shift in temperatureinducible expression systems [15,25]. However, sulA gene expression is also observed in the strain harboring the parental vector pCYTEXP1 without any cloned gene, suggesting that the biosynthesis of a complete protein is not required for the activation of the sulA transcription.…”

“…Considering these results, it could not be excluded that the previously reported transcription of the sulA: :lacZ fusion in response to temperature up-shift of GC4581 carrying CI857-controlled, lambda-based expression vectors [15] could be enhanced by an extended transcription of lambda lytic genes. The possibility of an unspeci¢c transcription of the reporter gene does not apply to E. coli GE864, in which SOS transcription has also been observed during thermal induction of a CI857-repressed recombinant gene [25]. Having a di¡erent origin and lacking any lambda prophage [17], this strain does not show detectable cell lysis upon thermal up-shift ( Fig.…”

Polylinker-Encoded Peptides Can Confer Toxicity to Recombinant Proteins Produced in Escherichia coli

“…When the product is an enzyme which retains its activity, toxicity can be an immediate consequence of the enzymatic activity over cell components (Bedouelle et al, 1990). In other cases, nondescribed properties of an eukaryotic enzyme seem to be intensified under the non‐natural environment provided by bacterial cells, such as the inhibition of bacterial DNA replication by a viral RNA polymerase (Benito et al, 1995). On the other hand, the removal of either hydrophobic (Sisk et al, 1992) or hydrophillic (Vidal et al, 1991) segments of structural proteins dramatically increases protein yield and plasmid stability.…”