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Tinel L, Rossignol S, Ciuraru R, Dumas S, George C. Photosensitized reactions initiated by 6-carboxypterin: singlet and triplet reactivity. Phys Chem Chem Phys 2016; 18:17105-15. [DOI: 10.1039/c6cp03119f] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
The photophysical and photochemical properties of 6-carboxypterin, a model compound for the pterin derivatives present at the sea surface microlayer, were studied and its singlet and triplet reactivity toward halides and selected organics demonstrated.
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Affiliation(s)
- L. Tinel
- Université Lyon 1
- CNRS
- UMR 5256
- IRCELYON
- Institut de recherches sur la catalyse et l'environnement de Lyon
| | - S. Rossignol
- Université Lyon 1
- CNRS
- UMR 5256
- IRCELYON
- Institut de recherches sur la catalyse et l'environnement de Lyon
| | - R. Ciuraru
- Université Lyon 1
- CNRS
- UMR 5256
- IRCELYON
- Institut de recherches sur la catalyse et l'environnement de Lyon
| | - S. Dumas
- Université Lyon 1
- CNRS
- UMR 5256
- IRCELYON
- Institut de recherches sur la catalyse et l'environnement de Lyon
| | - C. George
- Université Lyon 1
- CNRS
- UMR 5256
- IRCELYON
- Institut de recherches sur la catalyse et l'environnement de Lyon
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Horwitz BA, Gloria M, Berrocal T. A Spectroscopic View of Some Recent Advances in the Study of Blue Light Photoreception*. ACTA ACUST UNITED AC 2014. [DOI: 10.1111/j.1438-8677.1997.tb00651.x] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Hohl N, Galland P, Senger H, Eslava AP. Altered Pterin Patterns in Photoreceptor Mutants ofPhycomyces blakesleeanuswith DefectivemadlGene. ACTA ACUST UNITED AC 2014. [DOI: 10.1111/j.1438-8677.1992.tb00326.x] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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Abstract
Ultraviolet (UV) radiation can cause stresses or act as a photoregulatory signal depending on its wavelengths and fluence rates. Although the most harmful effects of UV on living cells are generally attributed to UV-B radiation, UV-A radiation can also affect many aspects of cellular processes. In cyanobacteria, most studies have concentrated on the damaging effect of UV and defense mechanisms to withstand UV stress. However, little is known about the activation mechanism of signaling components or their pathways which are implicated in the process following UV irradiation. Motile cyanobacteria use a very precise negative phototaxis signaling system to move away from high levels of solar radiation, which is an effective escape mechanism to avoid the detrimental effects of UV radiation. Recently, two different UV-A-induced signaling systems for regulating cyanobacterial phototaxis were characterized at the photophysiological and molecular levels. Here, we review the current understanding of the UV-A mediated signaling pathways in the context of the UV-A perception mechanism, early signaling components, and negative phototactic responses. In addition, increasing evidences supporting a role of pterins in response to UV radiation are discussed. We outline the effect of UV-induced cell damage, associated signaling molecules, and programmed cell death under UV-mediated oxidative stress.
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Witt FG, Aparicio PJ. EFFECTS OF SHORT PULSES OF BLUE LIGHT ON THE ALKALINIZATION ASSOCIATED WITH THE UPTAKE OF NO3− AND CL− BY THE GREEN ALGA MONORAPHIDIUM BRAUNII AND RELATED ACTION SPECTRA. Photochem Photobiol 2011. [DOI: 10.1111/j.1751-1097.1995.tb09878.x] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
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The Role of Cyanopterin in UV/Blue Light Signal Transduction of Cyanobacterium Synechocystis sp. PCC 6803 Phototaxis. ACTA ACUST UNITED AC 2010; 51:969-80. [DOI: 10.1093/pcp/pcq059] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022]
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7
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Jaramillo P, Coutinho K, Canuto S. Solvent Effects in Chemical Processes. Water-Assisted Proton Transfer Reaction of Pterin in Aqueous Environment. J Phys Chem A 2009; 113:12485-95. [DOI: 10.1021/jp903638n] [Citation(s) in RCA: 59] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Affiliation(s)
- Paula Jaramillo
- Instituto de Física, Universidade de São Paulo, CP 66318, 05314-970, São Paulo, SP, Brazil
| | - Kaline Coutinho
- Instituto de Física, Universidade de São Paulo, CP 66318, 05314-970, São Paulo, SP, Brazil
| | - Sylvio Canuto
- Instituto de Física, Universidade de São Paulo, CP 66318, 05314-970, São Paulo, SP, Brazil
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Cassola A, Parrot M, Silberstein S, Magee BB, Passeron S, Giasson L, Cantore ML. Candida albicans lacking the gene encoding the regulatory subunit of protein kinase A displays a defect in hyphal formation and an altered localization of the catalytic subunit. EUKARYOTIC CELL 2004; 3:190-9. [PMID: 14871949 PMCID: PMC329502 DOI: 10.1128/ec.3.1.190-199.2004] [Citation(s) in RCA: 61] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
The fungal pathogen Candida albicans switches from a yeast-like to a filamentous mode of growth in response to a variety of environmental conditions. We examined the morphogenetic behavior of C. albicans yeast cells lacking the BCY1 gene, which encodes the regulatory subunit of protein kinase A. We cloned the BCY1 gene and generated a bcy1 tpk2 double mutant strain because a homozygous bcy1 mutant in a wild-type genetic background could not be obtained. In the bcy1 tpk2 mutant, protein kinase A activity (due to the presence of the TPK1 gene) was cyclic AMP independent, indicating that the cells harbored an unregulated phosphotransferase activity. This mutant has constitutive protein kinase A activity and displayed a defective germinative phenotype in N-acetylglucosamine and in serum-containing medium. The subcellular localization of a Tpk1-green fluorescent protein (GFP) fusion protein was examined in wild-type, tpk2 null, and bcy1 tpk2 double mutant strains. The fusion protein was observed to be predominantly nuclear in wild-type and tpk2 strains. This was not the case in the bcy1 tpk2 double mutant, where it appeared dispersed throughout the cell. Coimmunoprecipitation of Bcy1p with the Tpk1-GFP fusion protein demonstrated the interaction of these proteins inside the cell. These results suggest that one of the roles of Bcy1p is to tether the protein kinase A catalytic subunit to the nucleus.
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Affiliation(s)
- Alejandro Cassola
- Cátedra de Microbiología, Facultad de Agronomía, Universidad de Buenos Aires, IBYF-CONICET, C1417DSE Buenos Aires, Argentina
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Thomas AH, Lorente C, Capparelli AL, Martínez CG, Braun AM, Oliveros E. Singlet oxygen (1deltag) production by pterin derivatives in aqueous solutions. Photochem Photobiol Sci 2003; 2:245-50. [PMID: 12713224 DOI: 10.1039/b209993d] [Citation(s) in RCA: 77] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Six compounds of the pterin family (pterin, 6-carboxypterin, 6-formylpterin, folic acid, biopterin and neopterin) have been investigated for their efficiencies of singlet oxygen (O2(1deltag)) production and quenching in aqueous solutions. The quantum yields of 1O2 production (phidelta) have been determined by measurements of the 1O2 luminescence in the near-infrared (1270 nm) upon continuous excitation of the sensitizer. Under our experimental conditions, all studied compounds (except folic acid) are relatively efficient 1O2 sensitizers with phidelta values of up to 0.47. Results show that the nature of the substituent at position 6 on the pterin moiety, as well as the pH, affect considerably the capacity of pterins to produce 1O2. All compounds investigated are efficient 1O2 quenchers: the rate constant of 1O2 total quenching (kt) by folic acid (3.0(+/- 0.3) x 10(7) M(-1) s(-1)) is one order of magnitude larger than those for the other pterin derivatives investigated (1.4(+/- 0.1) x 10(6) M(-1) s(-1) to 2.9(+/- 0.3) x 10(6) M(-1) s(-1)).
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Affiliation(s)
- Andrés H Thomas
- Instituto de Investigaciones Fisicoquímicas Teóricas y Aplicadas, Universidad Nacional de, La Plata, Casilla de Correo 16, Sucursal 4 (1900) La Plata, Argentina
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Thomas AH, Lorente C, Capparelli AL, Pokhrel MR, Braun AM, Oliveros E. Fluorescence of pterin, 6-formylpterin, 6-carboxypterin and folic acid in aqueous solution: pH effects. Photochem Photobiol Sci 2002; 1:421-6. [PMID: 12856711 DOI: 10.1039/b202114e] [Citation(s) in RCA: 106] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Steady-state and time-resolved studies have been performed on four compounds of the pterin family (pterin, 6-carboxypterin, 6-formylpterin and folic acid) in aqueous solution, using the single photon counting technique. The fluorescence characteristics (spectra, quantum yields, lifetimes) of these compounds and their dependence on the pH have been investigated. Most pterins can exist in two acid-base forms over the pH range between 3 and 13. Emission spectra and excitation spectra were obtained for both forms of each compound studied. Fluorescence quantum yields (phi(F)) in acidic and basic media were measured. The phi(F) of folic acid (< 0.005 in both media) is very low compared to those of pterin (0.27 in basic media and 0.33 in acidic media), 6-carboxypterin (0.18 in basic media and 0.28 in acidic media) and 6-formylpterin (0.07 in basic media and 0.12 in acidic media). The variation in integrated fluorescence intensity and fluorescence lifetimes (tau(F)) was analysed as a function of pH. Dynamic quenching by OH- was observed and the corresponding bimolecular rate constants for quenching of fluorescence (k(q)) were calculated. The reported values for k(q) (M(-1) s(-1)) are 3.6 x 10(9), 1.9 x 10(9) and 1.1 x 10(10) M(-1) s(-1) for pterin, 6-carboxypterin and 6-formylpterin, respectively.
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Affiliation(s)
- Andrés H Thomas
- Instituto de Investigaciones Fisicoquímica Teóricas y Aplicadas (INIFTA), Universidad Nacional de La Plata, Casilla de Correo 16, Sucursal 4 (1900) La Plata, Argentina
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12
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Pereyra E, Mizyrycki C, Moreno S. Threshold level of protein kinase A activity and polarized growth in Mucor rouxii. MICROBIOLOGY (READING, ENGLAND) 2000; 146 ( Pt 8):1949-1958. [PMID: 10931899 DOI: 10.1099/00221287-146-8-1949] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
A model system to study the involvement of cAMP-mediated regulation of a cellular process such as hyphal morphogenesis was investigated. Impairment of polarized growth was observed when Mucor rouxii sporangiospores were grown in the presence of N(6)-cAMP analogues and of SQ 65,442, a cAMP phosphodiesterase inhibitor. Together with an effect on isodiametric growth, there was increased pigmentation, increased cell fragility and loss of cell adhesiveness. The total effect on morphology was attained even after adding the compounds shortly before germ-tube emergence; when added after this time growth continued in a non-polarized form and rounding of the germ tip was observed. The morphological effect was observed under all the nutritional and environmental conditions studied (aerobic conditions and defined medium with maltose or glucose, Casamino acids medium with glucose, or rich medium; anaerobic conditions with rich medium; and following a shift from anaerobiosis to aerobiosis). The time of germ-tube emergence, and the size of the cell at this time, was dependent on the growth medium. Protein kinase A (PKA) specific activity was followed during the germination process under three growth conditions. It was found that the total activity of PKA correlated with differentiation and not with growth, and that the total specific activity at the time of germination was the same, independent of the culture medium. The time of germ-tube emergence correlated with the time of attainment of a threshold level of PKA total specific activity. The concentration of dibutyryl-cAMP needed to promote isodiametric growth correlated with the total units of activity of PKA to be activated per cell. It was concluded that PKA is involved in the morphogenetic process of the fungus grown under all the nutritional and ambient conditions tested.
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Affiliation(s)
- Elba Pereyra
- Departamento de Quı́mica Biológica, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Ciudad Universitaria, Pabellón 2, Piso 4, 1428 Buenos Aires, Argentina1
| | - Cynthia Mizyrycki
- Departamento de Quı́mica Biológica, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Ciudad Universitaria, Pabellón 2, Piso 4, 1428 Buenos Aires, Argentina1
| | - Silvia Moreno
- Departamento de Quı́mica Biológica, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Ciudad Universitaria, Pabellón 2, Piso 4, 1428 Buenos Aires, Argentina1
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Study of the photolysis of folic acid and 6-formylpterin in acid aqueous solutions. J Photochem Photobiol A Chem 2000. [DOI: 10.1016/s1010-6030(00)00304-x] [Citation(s) in RCA: 71] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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14
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Suárez G, Cabrerizo FM, Lorente C, Thomas AH, Capparelli AL. Study of the photolysis of 6-carboxypterin in acid and alkaline aqueous solutions. J Photochem Photobiol A Chem 2000. [DOI: 10.1016/s1010-6030(99)00224-5] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
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15
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Galland P, Eslava AP, Alvarez MI. Photoreception and Phototropism in Phycomyces: Antagonistic Interactions between Far-UV, Blue, and Red Light. Photochem Photobiol 1997. [DOI: 10.1111/j.1751-1097.1997.tb03241.x] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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Kritsky M, Lyudnikova T, Mironov E, Moskaleva I. The UV radiation-driven reduction of pterins in aqueous solution. JOURNAL OF PHOTOCHEMISTRY AND PHOTOBIOLOGY B-BIOLOGY 1997. [DOI: 10.1016/s1011-1344(96)07451-9] [Citation(s) in RCA: 39] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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17
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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.
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Affiliation(s)
- J Maier
- Institut für Chemische Pflanzenphysiologie, Universität Tübingen, Germany
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Tillmanns S, Senger H, Galland P. REDUCED NEAR-UV SENSITIVITY IN Phycomyces MUTANTS AFFECTED IN THE BIOSYNTHESIS OF 6,7-DIMETHYL-8-RIBITYLLUMAZINE. Photochem Photobiol 1995. [DOI: 10.1111/j.1751-1097.1995.tb02389.x] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Malhotra K, Kim ST, Batschauer A, Dawut L, Sancar A. Putative blue-light photoreceptors from Arabidopsis thaliana and Sinapis alba with a high degree of sequence homology to DNA photolyase contain the two photolyase cofactors but lack DNA repair activity. Biochemistry 1995; 34:6892-9. [PMID: 7756321 DOI: 10.1021/bi00020a037] [Citation(s) in RCA: 166] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
The putative blue-light photoreceptor genes of Arabidopsis thaliana and Sinapis alba (mustard) are highly homologous to the DNA repair genes encoding DNA photolyases. The photoreceptors from both organisms were overexpressed in Escherichia coli, purified, and characterized. The photoreceptors contain two chromophores which were identified as flavin adenine dinucleotide and methenyltetrahydrofolate. This chromophore composition suggests that the blue light photoreceptor may initiate signal transduction by a novel pathway which involves electron transfer. Despite the high degree of sequence identity to and identical chromophore composition with photolyases, neither photoreceptor has any photoreactivating activity.
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Affiliation(s)
- K Malhotra
- Department of Biochemistry and Biophysics, University of North Carolina School of Medicine, Chapel Hill 27599, USA
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Maier J, Ninnemann H. INHIBITION OF LIGHT-DEPENDENT PHOTOMORPHOGENESIS OF SPORANGIOPHORES FROM Phycomyces blakesleeanus BY APPLICATION OF PTERIDINE BIOSYNTHESIS INHIBITORS†. Photochem Photobiol 1995. [DOI: 10.1111/j.1751-1097.1995.tb03962.x] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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Maier J, Ninnemann H. Biosynthesis of pteridines in Neurospora crassa, Phycomyces blakesleeanus and Euglena gracilis: detection and characterization of biosynthetic enzymes. Photochem Photobiol 1995; 61:43-53. [PMID: 7899493 DOI: 10.1111/j.1751-1097.1995.tb09241.x] [Citation(s) in RCA: 27] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
Occurrence, biosynthesis and some functions of tetrahydrobiopterin (H4biopterin) in animals are well known. The biochemistry of H4biopterin in other organisms than animals was hitherto not widely investigated. Recently H4biopterin was found in the phytoflagellate Euglena gracilis, in the zygomycete Phycomyces blakesleeanus and in the ascomycete Neurospora crassa. In Euglena, Neurospora and Phycomyces the enzymatic activities of GTP cyclohydrolase I, 6-pyruvoyl tetrahydropterin synthase and sepiapterin reductase are detectable and the biosynthesis follows the same steps as were shown for animals. The biosynthetic enzymes, however, show a much lower sensitivity to those inhibitors that act on vertebrate enzymes. 2,4-Diamino-6-hydroxypyrimidine as inhibitor of GTP cyclohydrolase I and N-acetylserotonin or N-methoxyacetylserotonin as inhibitors of sepiapterin reductase can decrease pteridine biosynthesis significantly, in vitro and in vivo. The apparent Km values are in general higher when compared with the respective animal enzymes. In Neurospora, the conversion of GTP to dihydroneopterin triphosphate was closely associated with subsequent production of 6-hydroxymethyl-7,8-dihydropterin due to the high activity of dihydroneopterin aldolase, different from all other tested organisms. Investigations involving inhibition of pteridine synthesis might be a useful tool for evaluating the hypothesis that pteridines in fungi and plants are co-chromophores of various blue light-dependent, flavin-containing photoreceptors.
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Affiliation(s)
- J Maier
- Institut für Chemische Pflanzenphysiologie/Pflanzenbiochemie, Universität Tübingen, Germany
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23
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Kritsky MS. Contribution from coenzyme related molecules to evolution of photoreceptors. J Biol Phys 1995. [DOI: 10.1007/bf00700434] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022] Open
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Affiliation(s)
- H Ninnemann
- Institut für Chemische Pflanzenphysiologie/Pflanzenbiochemie, Universität Tübingen, Germany
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Campuzano V, Galland P, Senger H, Alvarez MI, Eslava AP. Isolation and characterization of phototropism mutants of Phycomyces insensitive to ultraviolet light. Curr Genet 1994; 26:49-53. [PMID: 7954896 DOI: 10.1007/bf00326304] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
Phototropism mutants of the zygomycete fungus Phycomyces blakesleeanus were isolated on the basis of their loss of responsivity to UV light. Four of these mutants had retained a partial sensitivity to near-UV and to blue light. Gravitropism and the avoidance response were unaffected in these mutants. One mutant, A909, had lost most of its sensitivity to near-UV and blue light while the sensitivity to far-UV light was only slightly affected. Additionally, the gravitropic and the avoidance responses were significantly reduced in A909. A complementation analysis of the five strains of Phycomyces with known phototropism mutants indicated that strains A896, A897, and A898 were defective in the madA gene, and that A905 was affected in the madC gene. In strain A909 the input, as well as the output, of the transduction chain is affected.
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Affiliation(s)
- V Campuzano
- Departamento de Microbiología y Genetica, Facultad de Biología, Universidad de Salamanca, Spain
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Fukshansky L. New trends in photobiology. JOURNAL OF PHOTOCHEMISTRY AND PHOTOBIOLOGY B-BIOLOGY 1993. [DOI: 10.1016/1011-1344(93)87082-x] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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Hohl N, Galland P, Senger H. Altered flavin patterns in photobehavioral mutants of Phycomyces blakesleeanus. Photochem Photobiol 1992; 55:247-55. [PMID: 1542706 DOI: 10.1111/j.1751-1097.1992.tb04234.x] [Citation(s) in RCA: 28] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
Flavins were extracted from sporangiophores of the lower fungus Phycomyces blakesleeanus and identified by HPLC with fluorescence detection. In the wild-type strain NRRL1555 they were found to be present at the following concentrations: riboflavin (5.5 x 10(-6) M), flavin mononucleotide (FMN) (4.0 x 10(-6) M) and flavin adenine dinucleotide (1.4 x 10(-6) M). The HPLC elution profiles of the wild type were compared to a set of behavioral mutants (genotype mad) with specific defects in their light-transduction pathway. The photoreceptor mutants C109 (madB), C111 (madB) and L1 (madC) had normal amounts of flavins. The most prominent changes were found in single mutants with a defective madA gene which contained about 25% of riboflavin and about 10% of FMN and FAD normally found in the wild type. A hypertropic mutant with a defective madH gene contained instead 80% of riboflavin and 120% of FMN and FAD. The double mutant L52 (madA madC) and the triple mutant L72 (madA madB madC) had normal amounts of FAD and FMN. This indicates that the madC mutation, which itself causes loss of light sensitivity and which affects the near-UV/blue-light receptor (Galland and Lipson, 1985, Photochem. Photobiol. 41, 331-335) functions as a restorer of the flavin content in a genetic madA background. The double mutant L51 (madA madB) had about 40% of FMN and FAD, suggesting that the madB mutation functions as a partial restorer of flavin content. The photogravitropic thresholds (450 nm) reported for the wild type and the madA and madH mutants were positively correlated to the endogeneous concentrations of FMN and FAD.(ABSTRACT TRUNCATED AT 250 WORDS)
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Affiliation(s)
- N Hohl
- Fachbereich Biologie/Botanik der Philipps-Universität Marburg, Fed. Rep. Germany
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