151
|
Abstract
UV radiation induces two major DNA damage products, the cyclobutane pyrimidine dimer (CPD) and, at a lower frequency, the pyrimidine (6-4) pyrimidinone dimer (6-4 product). Although Escherichia coli and Saccharomyes cerevisiae produce a CPD-specific photolyase that eliminates only this class of dimer, Arabidopsis thaliana, Drosphila melanogaster, Crotalus atrox, and Xenopus laevis have recently been shown to photoreactivate both CPDs and 6-4 products. We describe the isolation and characterization of two new classes of mutants of Arabidopsis, termed uvr2 and uvr3, that are defective in the photoreactivation of CPDs and 6-4 products, respectively. We demonstrate that the CPD photolyase mutation is genetically linked to a DNA sequence encoding a type II (metazoan) CPD photolyase. In addition, we are able to generate plants in which only CPDs or 6-4 products are photoreactivated in the nuclear genome by exposing these mutants to UV light and then allowing them to repair one or the other class of dimers. This provides us with a unique opportunity to study the biological consequences of each of these two major UV-induced photoproducts in an intact living system.
Collapse
Affiliation(s)
- C Z Jiang
- Section of Plant Biology, University of California, Davis, CA 95616, USA
| | | | | | | |
Collapse
|
152
|
Sametz-Baron L, T. GMB, Amit R, Herrera-Estrella A, Horwitz BA. Photoreactivation of UV-lnactivated Spores of Trichoderma harzianum. Photochem Photobiol 1997. [DOI: 10.1111/j.1751-1097.1997.tb01933.x] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
|
153
|
Maier J, Schmid R. Inhibition of pteridine biosynthesis eliminates blue-light dependent stimulation of red-light saturated photosynthesis in Laminaria saccharina (L.) Lamouroux. JOURNAL OF PHOTOCHEMISTRY AND PHOTOBIOLOGY. B, BIOLOGY 1997; 38:274-8. [PMID: 9203391 DOI: 10.1016/s1011-1344(96)07464-7] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
Blue-light stimulation of red light-saturated photosynthetic oxygen evolution in Laminaria saccharina (L.) Lamouroux could be abolished within 5 days by incubation in a solution of 2,4-diamino-6-hydroxypyrimidine (DAHP), an inhibitor of GTP-cyclohydrolase I (E.C.3.5.4.16) activity. Photosynthesis in red light was not detectably affected. GTP-cyclohydrolase I, which catalyses the first step in the biosynthetic pathway of pteridines, was shown to be active in Laminaria. Under conditions that lead to complete inhibition of the photosynthetic stimulation, DAHP reduced the content of the pteridines in the tissue considerably. The amount of pterin was about 14%, that of biopterin was about 45% and that of an unidentified pteridine was about 27% of those of the controls. By contrast, the total concentration of flavins (FAD + FMN - riboflavin) was not significantly affected. The results suggest that pterins may be involved in the response of photosynthesis to blue light, possibly participating in photoreception.
Collapse
Affiliation(s)
- J Maier
- Institut für Chemische Pflanzenphysiologie, Universität Tübingen, Germany
| | | |
Collapse
|
154
|
Landry LG, Stapleton AE, Lim J, Hoffman P, Hays JB, Walbot V, Last RL. An Arabidopsis photolyase mutant is hypersensitive to ultraviolet-B radiation. Proc Natl Acad Sci U S A 1997; 94:328-32. [PMID: 8990208 PMCID: PMC19334 DOI: 10.1073/pnas.94.1.328] [Citation(s) in RCA: 146] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023] Open
Abstract
Photolyases are DNA repair enzymes that use energy from blue light to repair pyrimidine dimers. We report the isolation of an Arabidopsis thaliana mutant (uvr2-1) that is defective in photorepair of cyclobutylpyrimidine dimers (CPDs). Whereas uvr2-1 is indistinguishable from wild type in the absence of UV light, low UV-B levels inhibit growth and cause leaf necrosis. uvr2-1 is more sensitive to UV-B than wild type when placed under white light after UV-B treatment. In contrast, recovery in darkness or in light lacking photoreactivating blue light results in equal injury in uvr2-1 and wild type. The uvr2-1 mutant is unable to remove CPDs in vivo, and plant extracts lack detectable photolyase activity. This recessive mutation segregates as a single gene located near the top of chromosome 1, and is a structural gene mutation in the type II CPD photolyase PHR1. This mutant provides evidence that CPD photolyase is required for plant survival in the presence of UV-B light.
Collapse
Affiliation(s)
- L G Landry
- The Boyce Thompson Institute for Plant Research, Cornell University, Ithaca, NY 14853-1801, USA
| | | | | | | | | | | | | |
Collapse
|
155
|
Affiliation(s)
- J M Staub
- Department of Biology, Yale University, New Haven, CT 06520-8104, USA
| | | |
Collapse
|
156
|
Abstract
Our genetic information is constantly challenged by exposure to endogenous and exogenous DNA-damaging agents, by DNA polymerase errors, and thereby inherent instability of the DNA molecule itself. The integrity of our genetic information is maintained by numerous DNA repair pathways, and the importance of these pathways is underscored by their remarkable structural and functional conservation across the evolutionary spectrum. Because of the highly conserved nature of DNA repair, the enzymes involved in this crucial function are often able to function in heterologous cells; as an example, the E. coli Ada DNA repair methyltransferase functions efficiently in yeast, in cultured rodent and human cells, in transgenic mice, and in ex vivo-modified mouse bone marrow cells. The heterologous expression of DNA repair functions has not only been used as a powerful cloning strategy, but also for the exploration of the biological and biochemical features of numerous enzymes involved in DNA repair pathways. In this review we highlight examples where the expression of DNA repair enzymes in heterologous cells was used to address fundamental questions about DNA repair processes in many different organisms.
Collapse
Affiliation(s)
- A Memisoglu
- Harvard School of Public Health, Boston, MA 02115, USA
| | | |
Collapse
|
157
|
Kim ST, Malhotra K, Ryo H, Sancar A, Todo T. Purification and characterization of Drosophila melanogaster photolyase. Mutat Res 1996; 363:97-104. [PMID: 8676930 DOI: 10.1016/0921-8777(96)00003-1] [Citation(s) in RCA: 22] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
Animal-type photolyases have very limited sequence homology to microbial-type photolyases. We wanted to find out whether the two types of enzymes have different or similar biochemical and photochemical properties. In particular, the chromophore/cofactor composition of animal photolyases is of special interest since the presence and nature of a second chromophore in these enzymes are not known in contrast to the microbial photolyases which contain FAD cofactor, and folate or deazaflavin as second chromophores. We overproduced the Drosophila melanogaster photolyase in Escherichia coli using the cloned gene. The enzyme contains FAD and folate and thus belongs in the folate class of enzymes but with an action spectrum peak at 420 nm.
Collapse
Affiliation(s)
- S T Kim
- Department of Biochemistry and Biophysics, University of North Carolina School of Medicine, Chapel Hill 27599, USA
| | | | | | | | | |
Collapse
|
158
|
Abstract
The biological impact of any DNA damaging agent is a combined function of the chemical nature of the induced lesions and the efficiency and accuracy of their repair. Although much has been learned from microbes and mammals about both the repair of DNA damage and the biological effects of the persistence of these lesions, much remains to be learned about the mechanism and tissue-specificity of repair in plants. This review focuses on recent work on the induction and repair of DNA damage in higher plants, with special emphasis on UV-induced DNA damage products.
Collapse
Affiliation(s)
- Anne B. Britt
- Section of Plant Biology, University of California, Davis, California 95616
| |
Collapse
|
159
|
Abstract
Light control of plant development is most dramatically illustrated by seedling development. Seedling development patterns under light (photomorphogenesis) are distinct from those in darkness (skotomorphogenesis or etiolation) with respect to gene expression, cellular and subcellular differentiation, and organ morphology. A complex network of molecular interactions couples the regulatory photoreceptors to developmental decisions. Rapid progress in defining the roles of individual photoreceptors and the downstream regulators mediating light control of seedling development has been achieved in recent years, predominantly because of molecular genetic studies in Arabidopsis thaliana and other species. This review summarizes those important recent advances and highlights the working models underlying the light control of cellular development. We focus mainly on seedling morphogenesis in Arabidopsis but include complementary findings from other species.
Collapse
Affiliation(s)
- Albrecht Von Arnim
- Department of Biology, Yale University, New Haven, Connecticut 06520-8104
| | | |
Collapse
|
160
|
Funayama T, Mitani H, Shima A. Overexpression of Medaka (Oryzias latipes) photolyase gene in Medaka cultured cells and early embryos. Photochem Photobiol 1996; 63:633-8. [PMID: 8628755 DOI: 10.1111/j.1751-1097.1996.tb05667.x] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
To study the role and the regulation of the photolyase gene in the Medaka (small teleost), we constructed a eukaryotic expression plasmid of the Medaka photolyase gene and introduced it into Medaka cells in vivo and in vivo. The expression plasmid contains a cytomegalovirus enhancer and a thymidine kinase promoter to overexpress the photolyase gene of the Medaka. First, we transfected this construct into cultured Medaka cells and established several lines of transfectant. Every transfectant showed enhanced ability of pyrimidine dimer repair in the presence of fluorescent light. In the transfectant that showed the most enhanced ability of photorepair, the augmented transcription of photolyase gene was observed compared with that of progenitor OL32 cells. In this transfectant, we also observed an enhanced rate of UV survival with 20 min of fluorescent light treatment after irradiation with a 400 J/m2 UV sunlamp. Next, the expression construct was microinjected into the embryos of the Medaka at the one cell stage. Compared with the nontreated counterparts, the overexpression of a photolyase gene was detected in the microinjected embryos, but we failed to detect a significant increase in photo-reactivability of death at the midblastula stage.
Collapse
Affiliation(s)
- T Funayama
- Department of Biological Sciences, University of Tokyo, Japan.
| | | | | |
Collapse
|
161
|
Todo T, Ryo H, Yamamoto K, Toh H, Inui T, Ayaki H, Nomura T, Ikenaga M. Similarity among the Drosophila (6-4)photolyase, a human photolyase homolog, and the DNA photolyase-blue-light photoreceptor family. Science 1996; 272:109-12. [PMID: 8600518 DOI: 10.1126/science.272.5258.109] [Citation(s) in RCA: 202] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
Ultraviolet light (UV)-induced DNA damage can be repaired by DNA photolyase in a light-dependent manner. Two types of photolyase are known, one specific for cyclobutane pyrimidine dimers (CPD photolyase) and another specific for pyrimidine (6-4) pyrimidone photoproducts[(6-4)photolyase]. In contrast to the CPD photolyase, which has been detected in a wide variety of organisms, the (6-4)photolyase has been found only in Drosophila melanogaster. In the present study a gene encoding the Drosophila(6-4)photolyase ws cloned, and the deduced amino acid sequence of the product was found to be similar to the CPD photolyase and to the blue-light photoreceptor of plants. A homolog of the Drosophila (6-4)photolyase gene was also cloned from human cells.
Collapse
Affiliation(s)
- T Todo
- Radiation Biology Center, Kyoto University, Kyoto, Japan
| | | | | | | | | | | | | | | |
Collapse
|
162
|
Affiliation(s)
- A Sancar
- Department of Biochemistry and Biophysics, University of Nor Carolina School of Medicine, Chapel Hill, 27599, USA
| |
Collapse
|
163
|
Ahmad M, Cashmore AR. Seeing blue: the discovery of cryptochrome. PLANT MOLECULAR BIOLOGY 1996; 30:851-861. [PMID: 8639745 DOI: 10.1007/bf00020798] [Citation(s) in RCA: 69] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Affiliation(s)
- M Ahmad
- Plant Science Institute, University of Pennsylvania, Philadelpha, 19104, USA
| | | |
Collapse
|
164
|
Biswas S, Biswas BB. Metabolism of myo-inositol phosphates and the alternative pathway in generation of myo-inositol trisphosphate involved in calcium mobilization in plants. Subcell Biochem 1996; 26:287-316. [PMID: 8744269 DOI: 10.1007/978-1-4613-0343-5_10] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Affiliation(s)
- S Biswas
- Department of Biochemistry, Bose Institute, Calcutta, India
| | | |
Collapse
|
165
|
Affiliation(s)
- G Whitelam
- Department of Botany, University of Leicester, UK
| |
Collapse
|
166
|
|
167
|
Lin C, Robertson DE, Ahmad M, Raibekas AA, Jorns MS, Dutton PL, Cashmore AR. Association of flavin adenine dinucleotide with the Arabidopsis blue light receptor CRY1. Science 1995; 269:968-70. [PMID: 7638620 DOI: 10.1126/science.7638620] [Citation(s) in RCA: 255] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
The arabidopsis thaliana HY4 gene encodes CRY1, a 75-kilodalton flavoprotein mediating blue light-dependent regulation of seedling development. CRY1 is demonstrated here to noncovalently bind stoichiometric amounts of flavin adenine dinucleotide (FAD). The redox properties of FAD bound by CRY1 include an unexpected stability of the neutral radical flavosemiquinone (FADH.). The absorption properties of this flavosemiquinone provide a likely explanation for the additional sensitivity exhibited by CRY1-mediated responses in the green region of the visible spectrum. Despite the sequence homology to microbial DNA photolyases, CRY1 was found to have no detectable photolyase activity.
Collapse
Affiliation(s)
- C Lin
- Department of Biology, University of Pennsylvania, Philadelphia, 19104, USA
| | | | | | | | | | | | | |
Collapse
|
168
|
Affiliation(s)
- J E Hearst
- Department of Chemistry, University of California, Berkeley 94720-1460, USA
| |
Collapse
|
169
|
Abstract
Photolyase repairs ultraviolet (UV) damage to DNA by splitting the cyclobutane ring of the major UV photoproduct, the cis, syn-cyclobutane pyrimidine dimer (Pyr <> Pyr). The reaction is initiated by blue light and proceeds through long-range energy transfer, single electron transfer, and enzyme catalysis by a radical mechanism. The three-dimensional crystallographic structure of DNA photolyase from Escherichia coli is presented and the atomic model was refined to an R value of 0.172 at 2.3 A resolution. The polypeptide chain of 471 amino acids is folded into an amino-terminal alpha/beta domain resembling dinucleotide binding domains and a carboxyl-terminal helical domain; a loop of 72 residues connects the domains. The light-harvesting cofactor 5,10-methenyltetrahydrofolylpolyglutamate (MTHF) binds in a cleft between the two domains. Energy transfer from MTHF to the catalytic cofactor flavin adenine dinucleotide (FAD) occurs over a distance of 16.8 A. The FAD adopts a U-shaped conformation between two helix clusters in the center of the helical domain and is accessible through a hole in the surface of this domain. Dimensions and polarity of the hole match those of a Pyr <> Pyr dinucleotide, suggesting that the Pyr <> Pyr "flips out" of the helix to fit into this hole, and that electron transfer between the flavin and the Pyr <> Pyr occurs over van der Waals contact distance.
Collapse
Affiliation(s)
- H W Park
- Department of Biochemistry, University of Texas Southwestern Medical Center, Dallas 75235, USA
| | | | | | | |
Collapse
|