Inducible responses to dna damage in bacteria and mammalian cells

Abstract

INTRODUCTIONThis review summarizes current knowledge of the DNA damage-inducible SOS response in E. coli, with an emphasis on the historical development of experimentation in this area. Evidence for the existence of analogous responses to DNA damage in other bacteria, lower eukaryotes, and mammalian cells is also presented. The mechanistic basis in E. coli for one of the SOS responses, mutagenesis, is currently a subject of intensive study in many laboratories, and recent developments in this area are explored in greater detail. Mutagenesis in mammalian cells, which does not appear to conform to the SOS model, is the subject of a forthcoming review [Rossman and Klein, in press].For more detailed treatments of various aspects of the SOS response in bacteria and mammalian cells, other recent reviews are recommended: the SOS response in E. coli [Witkin, 1976;Oishi et al, 1981;Little and Mount, 1982; Gottesman, 1984; Walker, 19841; pKMlOl [Strike and Lodwick, 19871; lambda prophage induction [Roberts and Devoret, 1983; Elespuru, 19841; DNA repair [Hanawalt et al, 1979;Defais et al, 1983; Walker et al, 19851; the SOS response in mammalian cells [Radman, 1980;Sarasin, 1985;Rossman and Klein, 1985; Lambert and Garrels, 19861. The contents of this publication do not necessarily reflect the views or policies of the Department of Health and Human Services, nor does mention of trade names, commercial products, or organizations imply endorsement by the US Government.By acceptance of this article, the publisher or recipient acknowledges the right of the US Government to retain a nonexclusive, royalty-free license in and to any copyright covering the article.Published 1987 by Alan R. Liss, Inc. Elespuru THE SOS RESPONSE IN E. coliObservations of apparently unrelated phenomena (virus reactivation, mutagenesis, prophage induction, filamentation) in different genetic backgrounds in E. coli led to a unifying hypothesis called the "SOS response" [Radman, 19751. The "SOS" hypothesis suggested "the existence of a DNA repair system which is normally repressed but which is induced by DNA damage". Two early concepts were critical to the development of the SOS model. One was that mutagenesis and repair of DNA damage depended on an inducible cellular process [Sedgewick, 1975; Witkin, 19761. This concept developed from the experiments of Weigle and others, which showed that survival and mutagenesis of UV-irradiated lambda phage depended on the irradiation of the host E. coli and was inhibited by the presence of chloramphenicol Weigle, 1953; Defais et al, 19761. The second concept, of coordinate regulation of responses to DNA damage, arose from genetic experiments. Mutations in certain genes (rec and lex) resulted in the abolition of all of the known responses to genetic damage under study (Weigle reactivation, mutagenesis, lambda prophage induction, filamentation) or to their temperature-dependent expression witkin, 1967, 1969; Castellazzi et al, 1972; Ishii and Kondo, 19751. The abolition of "Weigle reactivation" (enhanced survival o...

Enhancement of transformation rates in higher plants by low-dose irradiation: Are DNA repair systems involved in the incorporation of exogenous DNA into the plant genome?

“…In animal and plant cells the fiequency of transformation can be significantly raised when exogenous DNA is directly microinjected into the nucleus [41,25]. These results and the observation that synchronized protoplasts in the S-or Mphase of the cell cycle can be efficiently transformed [23] have led to the assumption that the nuclear membrane might be a substantial barrier for the import and incorporation of foreign DNA [23], Irradiation of plant cells, like in prokaryotes and other eukaryotes [7], results in single-strand breaks, base damage and, to a lesser extent, double-strand breaks [10]. Excision repair has been demonstrated in irradiated protoplasts ofHaplopappus, Nicotiana and Petunia [11].…”

Prophage Induction and Expression of Prophage-EncodedVirulence Factors in Group A Streptococcus Serotype M3 StrainMGAS315

“…It is worth noting that our results regarding the effects of mitomycin C and hydrogen peroxide on phage induction in GAS might have important implications for antibiotic treatment of GAS infections. Mitomycin C, hydrogen peroxide, and fluoroquinolone antibiotics, which are potent inducers of prophage lambda and the SOS response, promote DNA damage (6,8). Although we did not examine the effects of DNA-damaging antibiotics on phage induction and the expression of phage-encoded virulence factors in GAS, it is possible that antibiotics that disrupt prokaryote DNA replication could lead to phage induction and the expression of phage-encoded virulence factors in GAS.…”

The Myth and Reality of Reversal of Aging by Hormesis

“…There is considerable homology between the two families 41. Specialized responses to environmental stresses like heat, cold, nutrient limitation, salinity, and osmolarity have been characterized and reviewed 42,43…”

“…41 Specialized responses to environmental stresses like heat, cold, nutrient limitation, salinity, and osmolarity have been characterized and reviewed. 42,43 A major role for the induced heat shock Hsp70 family members is in chaperoning the refolding of denatured protein, which can rejuvenate protein function. Abnormal proteins can be refolded by this ATP-driven process and irreparable proteins can be degraded by the ATP ubiquitin pathway.…”