Structural insights into the regulation of SOS mutagenesis

• Autorzy: Gonzales M. , Frank E.G. , McDonald J.P. , Levine A.S. , Woodgate R.
• Języki publikacji: EN

Abstrakty

EN

The Escherichia coli Umu proteins are best characterized by their role in damage inducible mutagenesis. Recently, we discovered that the intracellular levels of the UmuD and UmuC proteins are kept to a minimum by the Lon serine protease. Studies with the Salmonella typhimurium UmuD protein (which is 73% homologous with its E. coli counterpart) revealed that it too is degraded by Lon, suggesting that both UmuD proteins share conserved structural motifs. In contrast, E. coli UmuD' is removed from the cell by the ClpXP serine protease, but only when it is in a heterodimer complex with UmuD. We have generated deletion mutants of UmuD' and have co-expressed the mutant proteins with UmuD1 (a non-cleavable UmuD protein). By assaying the sensitivity of the mutant UmuD'-UmuD1 complex to ClpXP, we have been able to map regions of UmuD' that appear essential for efficient UmuD'-UmuD heterodimer formation. Previous experiments have suggested that the in vivo posttranslational processing of UmuD to UmuD' is inefficient. We have, however, discovered that limited cleavage occurs in an undamaged cell, but that these small amounts of UmuD' are rapidly degraded by ClpXP, thus giving rise to the appearance of inefficient cleavage. The ClpXP protease therefore plays dual roles in regulating SOS mutagenesis: it keeps the basal levels of UmuD' to a minimum in undamaged cells but it also acts in damaged cells to reduce the elevated levels of mutagenically active UmuD' protein, thereby returning the cell to a resting non-mutable state.

Słowa kluczowe

EN

health; Salmonella typhimurium; proteolysis; protein; mutagenesis; Escherichia coli

• Wydawca: -
• Czasopismo: Acta Biochimica Polonica
• Rocznik: 1998
• Tom: 45
• Numer: 1
• Opis fizyczny: p.163-172,fig.

Twórcy

autor

Gonzales M.

• National Institute of Health, Bethesda, MD 20892-2725 USA

autor

Frank E.G.

autor

McDonald J.P.

autor

Levine A.S.

autor

Woodgate R.

Bibliografia

• 1. Friedberg, E.C., Walker, G.C. & Siede, W. (1995) DNA Repair and Mutagenesis. Ameri­can Society of Microbiology, Washington, DC.
• 2. Woodgate, R. & Levine, A.S. (1996) Damage inducible mutagenesis: Recent insights into the activities of the Umu family of mutagene­sis proteins; in Cancer Surveys: Genetic Insta­bility in Cancer (Lindahl, T., ed.) pp. 117-140, Cold Spring Harbor Laboratory Press, Cold Spring Harbor, New York.
• 3. Frank, E.G., Ennis, D.G., Gonzalez, M., Le­vine, A.S. & Woodgate, R. (1996) Regulation of SOS mutagenesis by proteolysis. Proc. Natl Acad. Sci. U.S.A. 93, 10291-10296.
• 4. Woodgate, R. & Ennis, D.G. (1991) Levels of chromosomaily encoded Umu proteins and re­quirements for in vivo UmuD cleavage. Mol. Gen. Genet 229, 10-16.
• 5. Shinagawa, H., Iwasaki, H., Kato, T. & Nakata, A. (1988) RecA protein-dependent cleavage of UmuD protein and SOS mutagene­sis. Proc. Natl Acad. Sci. U.S.A. 85, 1806- 1810.
• 6. Burckhardt, S.E., Woodgate, R., Scheuer­mann, R.H. & Echols, H. (1988) UmuD muta­genesis protein of Escherichia coli: Overpro­duction, purification and cleavage by RecA. Proc. Natl. Acad. Set U.S.A. 85. 1811-1815.
• 7. Nohmi, T., Battista, J.R., Dodson, L.A. & Walker, G.C. (1988) RecA-mediated cleavage activates UmuD for mutagenesis: Mechanistic relationship between transcriptional derepres­sion and posttranslational activation. Proc. Natl Acad. Sci. U.S.A. 85, 1816-1820.
• 8. Frank, E.G., Gonzalez, M., Ennis, D.G., Le­vine, A.S. & Woodgate, R. (1996) In vivo stabil­ity of the Umu mutagenesis proteins: A major role for RecA. J. Bacteriol 178, 3550-3556.
• 9. Battista, J.R., Ohfca, T., Nohmi, T., Sun, W. & Walker, G.C. (1990) Dominant negative umuD mutations decreasing RecA-mediated cleavage suggest roles for intact UmuD in modulation of SOS mutagenesis. Proc. Natl Acad. ScL U.S.A. 87, 7190-7194.
• 10. Churchward, G., Belin, D. & Nagamine, Y. (1984) A pSClOl-derived plasmid which shows no sequence homology to other com­monly used cloning vectors. Gene 31, 165- 171.
• 11. Peat, T.S., Frank, E.G., McDonald, J.P., Levine, A.S., Woodgate, R. & Hendrickson, W.A. (1996) The UmuD' protein filament and its potential role in damage induced muta­genesis. Structure 4, 1401-1412.
• 12. Thomas, S.M., Crowne, H.M., Pidsley, S.C. & Sedgwick, S.G. (1990) Structural characteriza­tion of the Salmonella typhimurium LT2 umu operon. J. Bacteriol 172, 4979-4987.
• 13. Smith, C.M., Koch, W.H., Franklin, S.B., Fos­ter, P.L., Cebula, T.A. & Eisenstadt, E. (1990) Sequence analysis of the Salmonella typhi­murium LT2 umuDC operon. J. Bacteriol 172, 4964-4978.
• 14. Sedgwick, S.G., Lodwick, D.L., Doyle, N., Crowne, H.M. & Strike, P. (1991) Functional complementation between chromosomal and plasmid mutagenic DNA repair genes. Mol Gen. Genet. 229, 428-436.
• 15. Koch, W.H., Kopsidas, G., Meffle, B., Levine, A.S. & Woodgate, R. (1996) Analysis of chi­meric UmuC proteins: Identification of re­gions in Salmonella typhimurium UmuC impor­tant for mutagenic activity. Mol. Gen. Genet 251, 121-129.
• 16. Levchenko, I., Luo, L. & Baker, T.A. (1995) Disassembly of the Mu transposase tetramer by the ClpX chaperone. Genes & Dev. 9, 2399- 2408.
• 17. Geuskens, V., Vogel, J.L., Grimaud, R., Des- met, L., Higgins, N.P. & Toussaint, A. (1991) Frameshift mutations in the bacteriophage Mu repressor geue can confer a trxina- dominant virulent phenotype to the phage. J. Bacteriol 173, 6578-6585.
• 18. Laachouch, J.E, Desmet, L., Geuskens, V., Gri­maud, R. & Toussaint, A. (1996) Bacterio­phage Mu repressor as a target for the Escheri­chia coli ATP-dependent Clp protease. EMBO J. 15, 437-444.
• 19. Wojtkowiak, D., Georgopoulos, C. & Zylicz, M. (1993) Isolation and characterization of ClpX, a new ATP-dependent specificity component of the Clp protease of Escherichia coli. J. BioL Chem. 268, 22609-22617.
• 20. Lehnherr, H. & Yarmolinsky, M.B. (1995) Ad­diction protein Phd of plasmid prophage Pi is a substrate of the ClpXP serine protease of Escherichia coli. Proc. Natl Acad. Sci. U.S.A. 92, 3274-3277.
• 21. Levchenko, I., Yamauchi, M. & Baker, T.A. (1997) ClpX and MuB interact with overlap­ping regions of Mu transposase: Implications for control of the transposition pathway. Genes & Dev. 11. 1561-1572.
• 22. Geuskens, V., Mhammedi-Alaoui, A., I)e9met, L. & Toussaint, A. (1992) Virulence in bacte­riophage Mu: A case of irans-dominant prote­olysis by the Escherichia coli Clp serine prote­ase. EMBOJ. 11, 5121-5127.
• 23. Mhammedi-Alaoui, A., Pato, M., Gama, M.-J. & Toussaint, A. (1994) A new component of bacteriophage Mu repiicative transposition machinery: The Escherichia coli ClpX protein. Mol Microbiol 11, 1109-1116.
• 24. Schweder, T., Lee, K.H., Lomovskaya, O. & Matin, A. (1996) Regulation of Escherichia coli starvation sigma factor (o*) by ClpXP prote­ase. J. Bacteriol. 178, 470-476.