Aberrant regulation of synthesis and degradation of viral proteins in coliphage lambda-infected UV-irradiated cells and in minicells

Journal Article · Thu Oct 01 04:00:00 EDT 1987 · J. Virol.; (United States)

OSTI ID:6122565

Shaw, J E; Epp, C; Pearson, M L; Reeve, J N

The patterns of bacteriophage lambda proteins synthesized in UV-irradiated Escherichia coli cells and in anucleate minicells are significantly different; both systems exhibit aberrations of regulation in lambda gene expression. In unirradiated cells or cells irradiated with low UV doses (less than 600 J/m2), regulation of lambda protein synthesis is controlled by the regulatory proteins CI, N, CII, CIII, Cro, and Q. As the UV dose increases, activation of transcription of the cI, rexA, and int genes by CII and CIII proteins fails to occur and early protein synthesis, normally inhibited by the action of Cro, continues. After high UV doses (greater than 2000 J/m2), late lambda protein synthesis does not occur. Progression through the sequence of regulatory steps in lambda gene expression is slower in infected minicells. In minicells, there is no detectable cII- and cIII-dependent synthesis of CI, RexA, or Int proteins and inhibition of early protein synthesis by Cro activity is always incomplete. The synthesis of early b region proteins is not subject to control by CI, N, or Cro proteins, and evidence is presented suggesting that, in minicells, transcription of the early b region is initiated at a promoter(s) within the b region. Proteolytic cleavage of the regulatory proteins O and N and of the capsid proteins C, B, and Nu3 is much reduced in infected minicells. Exposure of minicells to very high UV doses before infection does not completely inhibit late lambda protein synthesis.

• Research Organization: Univ. of Minnesota, St. Paul
• OSTI ID: 6122565
• Journal Information: J. Virol.; (United States), Journal Name: J. Virol.; (United States) Vol. 61:10; ISSN JOVIA
• Country of Publication: United States
• Language: English

Related Subjects

560130* -- Radiation Effects on Microorganisms
63 RADIATION, THERMAL, AND OTHER ENVIRON. POLLUTANT EFFECTS ON LIVING ORGS. AND BIOL. MAT.
BACTERIA
BACTERIOPHAGES
BIOLOGICAL EFFECTS
BIOLOGICAL RADIATION EFFECTS
BIOSYNTHESIS
ELECTROMAGNETIC RADIATION
ESCHERICHIA COLI
GENE REGULATION
GENES
GENETIC EFFECTS
GENETIC RADIATION EFFECTS
MICROORGANISMS
ORGANIC COMPOUNDS
PARASITES
PROTEINS
RADIATION EFFECTS
RADIATIONS
SYNTHESIS
TRANSCRIPTION
ULTRAVIOLET RADIATION
VIRUSES