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Schneider-Poetsch HAW, John G, Braun B. The Distribution of a Phytochrome-Like Protein in the FernPsilotum nudum.; An Immunoblotting Analysis of an Early Ancestor of all Vascular Plants. ACTA ACUST UNITED AC 2014. [DOI: 10.1111/j.1438-8677.1990.tb00154.x] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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Abstract
To characterize the nature of primary photoprocesses of phytochrome which serves as the red-far red reversible photoreceptor for photomorphogenesis in plants, viscosity dependence of the fluorescence lifetimes of phytochrome isolated from etiolated oat seedling (Avena sativa L.) has been investigated. The fluorescence decay of phytochrome exhibited approximately two components, one with lifetime in the range of 50-70 ps and another with 1.1-1.2 ns in phosphate buffer with or without 40-67% glycerol. However, relative amplitudes of these decay components were found to be strongly viscosity dependent. Thus, the longer decay component increased from 2-5% in phosphate buffer to approximately 20% in 67% glycerol-phosphate buffer. These results have been interpreted in terms of primary reaction from the excited singlet state of phytochrome, yielding a photoreversible intermediate whose rate of formation and decay were apparently viscosity-dependent. Further, the viscosity dependence is consistent with the primary reaction involving conformational changes of the chromophore/its apoprotein environment.
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FINLAY BJ, FENCHEL T. Photosensitivity in the Ciliated ProtozoonLoxodes: Pigment Granules, Absorption and Action Spectra, Blue Light Perception, and Ecological Significance1. ACTA ACUST UNITED AC 2007. [DOI: 10.1111/j.1550-7408.1986.tb05658.x] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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Plaza P, Mahet M, Martin MM, Angelini N, Malatesta M, Checcucci G, Lenci F. Spectroscopic study of the chromophore–protein association and primary photoinduced events in the photoreceptor of Blepharisma japonicum. Photochem Photobiol Sci 2005; 4:754-61. [PMID: 16121288 DOI: 10.1039/b417086e] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Blepharisma japonicum is a ciliated protozoan exhibiting a strong step-up photophobic response upon illumination. The photoreceptor chromophores responsible for this response have been identified to be hypericin-like chromophores (blepharismin and oxyblepharismin), complexed to a 200 kDa non-water-soluble protein. The present work opens up new perspectives on the primary phototransduction steps of B. japonicum's light perception through a joined approach by steady-state fluorescence spectroscopy, time-resolved fluorescence anisotropy and sub-picosecond transient absorption spectroscopy. The free chromophore of the light-adapted form of the cell (oxyblepharismin) was studied in various solvents and its spectroscopic properties, as well as its primary excited-state reactivity, compared with those of the corresponding pigment-protein complex, extracted by phosphate-concentration-step chromatography on a hydroxyapatite column. Fluorescence anisotropy together with SDS PAGE electrophoresis results confirm that oxyblepharismin is non-covalently bound to the apoprotein and show that, in the excited state, it is free to rotate in all directions within the binding site where it experiences a large local viscosity. Time-resolved anisotropy measurements on aromatic amino acids confirm that the molecular weight of the protein is of the order of 200 kDa. Although showing very similar steady-state spectra, free oxyblepharismin and its protein complex have noticeably different excited-state behaviours. In particular, the protein complex exhibits a pronounced short-lived absorption feature in the 640--750 nm range, decaying biexponentially in 4 ps and 56 ps. Those decays, also observed in other spectral regions, are not found in the corresponding kinetics of the isolated pigment in solution. This early behaviour of the protein complex might be the signature of the primary phototransduction process, possibly involving an electron transfer from the pigment to a neighbouring protein acceptor residue as it had been suggested in previous studies.
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Affiliation(s)
- Pascal Plaza
- UMR 8640 CNRS, Département de Chimie, Ecole Normale Supérieure, 24 rue Lhomond, 75005 Paris, France.
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Sgarbossa A, Checcucci G, Lenci F. Photoreception and photomovements of microorganisms. Photochem Photobiol Sci 2002; 1:459-67. [PMID: 12659155 DOI: 10.1039/b110629e] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Many freely motile microorganisms can perceive and transduce external photic stimuli to the motor apparatus, eventually moving, by means of various behavioural strategies, into environments in which the illumination conditions are the most favourable for their life. In different microorganisms, a wide range of chromophores operate as light detectors, each of them set in a special molecular pocket that, in its turn, can be linked to another component of the transduction chain. The diverse photosensors are organized in special (and in many cases dedicated) photoreceptor units or subcellular organelles. The main molecular mechanisms connecting the early event of photon absorption to the formation of the signalling state down to the dark steps of the transduction chain are discussed in a selected number of case examples. The possible importance of an intensive multidisciplinary approach to these problems in an evolutionary perspective is finally briefly outlined.
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Metzler DE, Metzler CM, Sauke DJ. Light and Life. Biochemistry 2001. [DOI: 10.1016/b978-012492543-4/50026-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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7
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Losi A. Fluorescence and Time-Resolved Photoacoustics of Hypericin Inserted in Liposomes: Dependence on Pigment Concentration and Bilayer Phase. Photochem Photobiol 1997. [DOI: 10.1111/j.1751-1097.1997.tb01926.x] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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8
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Wells TA, Losi A, Dai R, Scott P, Park SM, Golbeck J, Song PS. Electron Transfer Quenching and Photoinduced EPR of Hypericin and the Ciliate Photoreceptor Stentorin. J Phys Chem A 1997. [DOI: 10.1021/jp9612588] [Citation(s) in RCA: 24] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Todd A. Wells
- Departments of Chemistry and Biochemistry, University of Nebraska, Lincoln, Nebraska 68588-0304
| | - Aba Losi
- Departments of Chemistry and Biochemistry, University of Nebraska, Lincoln, Nebraska 68588-0304
| | - Renke Dai
- Departments of Chemistry and Biochemistry, University of Nebraska, Lincoln, Nebraska 68588-0304
| | - Paul Scott
- Departments of Chemistry and Biochemistry, University of Nebraska, Lincoln, Nebraska 68588-0304
| | - Su-Moon Park
- Departments of Chemistry and Biochemistry, University of Nebraska, Lincoln, Nebraska 68588-0304
| | - John Golbeck
- Departments of Chemistry and Biochemistry, University of Nebraska, Lincoln, Nebraska 68588-0304
| | - Pill-Soon Song
- Departments of Chemistry and Biochemistry, University of Nebraska, Lincoln, Nebraska 68588-0304
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Dai R, Yamazaki T, Yamazaki I, Song PS. Initial spectroscopic characterization of the ciliate photoreceptor stentorin. BIOCHIMICA ET BIOPHYSICA ACTA 1995; 1231:58-68. [PMID: 7640291 DOI: 10.1016/0005-2728(95)00056-o] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
Stentorin serves as the primary photosensor in the single cell ciliate, Stentor coeruleus, for its photophobic and phototactic response to light of visible wavelengths. We separated two subunits, stentorin-2A and -2B, from the previous stentorin complex ('stentorin-2') of greater than half a million molecular mass isolated from the photoreceptor organelle (pigment granule). Stentorin-2B bears the chromophore covalently linked to an approx. 50 kDa apoprotein, as determined by SDS-urea-PAGE. Partial amino acid sequences were obtained from this 50 kDa subunit. Its visible and CD spectra were found to be similar to those of stentorin-2. The steady-state and time-resolved fluorescence spectra of stentorin-2B, in H2O and D2O buffers, were also similar to those of stentorin-2. This suggests that the 50 kDa subunit retains the spectral integrity and primary photoreactivity of the stentorin-complex. The picosecond time-resolved fluorescence study revealed that the short picosecond emission component (tau F approximately equal to 8-10 ps) was the predominant emitting species in stentorin-2B and -2, followed by longer decaying species. No deuterium solvent effect was seen in this fast-decaying species. The possible mechanism for the primary photoreaction appears to involve electron transfer coupled with proton transfer.
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Affiliation(s)
- R Dai
- Department of Chemistry, University of Nebraska, Lincoln 68588-0304, USA
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11
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Lenci F, Angelini N, Ghetti F, Sgarbossa A, Losi A, Vecli A, Viappiani C, Taroni P, Pifferi A, Cubeddu R. Spectroscopic and photoacoustic studies of hypericin embedded in liposomes as a photoreceptor model. Photochem Photobiol 1995; 62:199-204. [PMID: 7638267 DOI: 10.1111/j.1751-1097.1995.tb05259.x] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
In photoresponsive ciliates, like Blepharisma japonicum and Stentor coeruleus, the photoreceptor pigments responsible for photomotile reactions are hypericin-type chromophores packed in highly osmiophilic subpellicular granules. Lipopsomes loaded with hypericin can constitute a simple model system, appropriate for understanding the primary light-induced molecular events triggering the sensory chain in these microorganisms. Optical absorption, steady-state and time-resolved fluorescence and pulsed photoacoustic calorimetry have been used to measure spectral distributions, fluorescence lifetimes, radiative and radiationless transition quantum yields of hypericin when assembled into egg L-alpha-phosphatidylcholine liposomes. With respect to hypericin ethanol solutions, both absorption and fluorescence maxima are 5 nm red shifted when the pigment is inserted into the lipidic microenvironment, regardless of the hypericin local concentration. Increasing by 100 times the hypericin local concentration decreases the relative fluorescence quantum yield by a factor of around 150 and the fraction of thermally released energy, conversely, increases from 0.6 to 0.9. From the analysis of fluorescence lifetimes and their relative amplitudes it appears that a subnanosecond living component is predominant at the highest hypericin local concentrations.
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Affiliation(s)
- F Lenci
- Istituto Biofisica CNR, Pisa, Italy
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PODESTA ADRIANO, MARANGONI ROBERTO, VILLANI CHIARA, COLOMBETTI GIULIANO. A Rhodopsin-like Molecule on the Plasma Membrane of Fabrea salina. J Eukaryot Microbiol 1994. [DOI: 10.1111/j.1550-7408.1994.tb01518.x] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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13
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Fabczak H, Fabczak S, Song PS, Checcucci G, Ghetti F, Lenci F. Photosensory transduction in ciliates. Role of intracellular pH and comparison between Stentor coeruleus and Blepharisma japonicum. JOURNAL OF PHOTOCHEMISTRY AND PHOTOBIOLOGY. B, BIOLOGY 1993; 21:47-52. [PMID: 8289111 DOI: 10.1016/1011-1344(93)80163-4] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
To test the hypothesis that light signal transduction in the unicellular ciliates Stentor coeruleus and Blepharisma japonicum involves a change in intracellular pH as an initial signal following photoexcitation, we studied the dependence of the photophobic responses of the cells to changes in extracellular pH and to reagents that specifically affect intracellular pH. The extracellular pH can modify not only the intracellular pH, but can even reverse the sign of the pH gradient across the cell membrane. Thus, as predicted by the hypothesis, low extracellular pH reversibly inhibited the photophobic response of the ciliates. The intracellular pH-modulating reagents tested included ammonium chloride, a membrane-permeable weak acid that lowers the intracellular pH, and the protonophores carbonylcyanide m-chlorophenyl-hydrazone (CCCP) and carbonylcyanide p-(trifluoromethoxy)-phenyl-hydrazone (FCCP), which collapse the pH gradient across the cell membrane. The low pH and protonophore treatments caused a gradual inhibition of the photophobic responses in both ciliates. The observed reduction of the responsiveness of the cells to visible light can be attributed to the alteration of the intracellular pH, which is suggested to play a specific role in the photosensory transduction in both Stentor coeruleus and Blepharisma japonicum.
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Affiliation(s)
- H Fabczak
- Department of Cell Biology, Polish Academy of Science, Warsaw
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Yamazaki T, Yamazaki I, Nishimura Y, Dai R, Song PS. Time-resolved fluorescence spectroscopy and photolysis of the photoreceptor blepharismin. BIOCHIMICA ET BIOPHYSICA ACTA 1993; 1143:319-26. [PMID: 8329440 DOI: 10.1016/0005-2728(93)90203-r] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
Blepharismin is the photoreceptor for the photophobic response in the ciliate Blepharisma japonicum (Scevoli, P., Bisi, F., Colombetti, G., Ghetti, F., Lenci, F., and Passarelli, V. (1987) J. Photochem. Photobiol.: B. Biol. 1, 75-84; Lenci, F., Ghetti, F., Gioffre, D., Heelis, P.F., Thomas, B., Phillips, G.O., and Song, P.-S. (1989) J. Photochem. Photobiol.: B. Biol. 3, 449-453). Blepharismin was solubilized from the red cells with 2% n-octylglucopyranoside. A crude pigment-protein preparation was then successively subjected to Bio-Gel A1.5 filtration, FPLC/hydroxyapatite and FPLC/DEAE ion-exchange chromatography. At least two spectrally distinct forms of blepharismin, with the respective absorbance maxima at 597 +/- 1 and 601 +/- 1 nm, were resolved. The steady state fluorescence emission maxima were at 602.5 and 617.5 nm, respectively. The fluorescence decay curves for these pigments were non-exponential. The major component possesses relatively short fluorescence lifetime (200-500 ps) for the former, according to a global analysis. This analysis suggests that the excited state of the shorter wavelength-absorbing form of blepharismin undergoes primary photoprocess faster than that of the free parental chromophore hypericin. Photolysis of blepharismin in solution yielded a irreversible product, accompanied by a 10-12 nm bathochromic shift of the absorbance maximum. However, the mechanistic nature of the time-resolved fluorescence and the photochemistry of blepharismin remains to be elucidated.
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Affiliation(s)
- T Yamazaki
- Department of Chemical Process Engineering, Hokkaido University, Sapporo, Japan
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Fabczak S, Fabczak H, Tao N, Song PS. Photosensory transduction in ciliates. I. An analysis of light-induced electrical and motile responses in Stentor coeruleus. Photochem Photobiol 1993; 57:696-701. [PMID: 8506399 DOI: 10.1111/j.1751-1097.1993.tb02940.x] [Citation(s) in RCA: 27] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
Light-induced membrane potential changes and motile responses have been studied in Stentor cells with intracellular microelectrodes and video microscopy, respectively. Intracellular microelectrode recordings showed that step-up increase in light intensity induced an electrical membrane response which consisted of an initial membrane depolarization (photoreceptor potential) followed by an action potential and maintaining phase of depolarization (afterdepolarization). The amplitude of the receptor potential is dependent on the intensity of light stimulus and the action potential appears with a lag period (latency) after the onset of light stimulus. The extent of the membrane afterdepolarization is dependent on the intensity and duration of stimulus used. A close time correlation has been established between the latency for the action potential and the onset of ciliary reversal (stop response). A time correlation was also observed between the duration of the membrane afterdepolarization and the duration of backward swimming. The action spectrum for the photoreceptor potential amplitude of Stentor resembled the action spectra for the latency of ciliary reversal and the photoresponsiveness, indicating that the photomovement response and membrane potential changes are coupled through the same photosensor system. A hypothesis on the photosensory transduction chain in Stentor is discussed according to which the photoreceptors and the ciliary apparatus is mediated by the membrane potential changes.
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Affiliation(s)
- S Fabczak
- Department of Cell Biology, Polish Academy of Sciences, Warsaw
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Abstract
Green light (510-565 nm) constitutes a significant portion of the visible spectrum impinging on biological systems. It plays many different roles in the biochemistry, physiology and structure of plants and animals. In only a relatively small number of responses to green light is the photoreceptor known with certainty or even provisionally and in even fewer systems has the chain of events leading from perception to response been examined experimentally. This review provides a detailed view of those biological systems shown to respond to green light, an evaluation of possible photoreceptors and a review of the known and postulated mechanisms leading to the responses.
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Affiliation(s)
- R M Klein
- Botany Department, University of Vermont, Burlington 05405
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Grajek H, Bojarski C, Zurkowska G, Drabent R. The influence of fluorescence concentration quenching on the emission anisotropy of flavins in glycerine-water solutions. Photochem Photobiol 1992; 55:381-7. [PMID: 1561236 DOI: 10.1111/j.1751-1097.1992.tb04251.x] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
The measurements of the emission anisotropy r/r0 of flavomononucleotide (FMN) within a range of concentrations of 10(-5)-10(-1) mol/L in glycerine-water solutions of different viscosities--0.056 Pa/s (system I) and 0.256 Pa/s (system II) have been carried out. In the range of high concentrations the repolarization effect due to the sharp drop of the quantum yield has been observed. The experimental results have been compared with theoretical expressions evaluated by taking into account both concentration and rotation depolarization. A good agreement on the values of the theoretical parameters obtained from independent measurements has been found. It has been stated that in the investigated systems the excitation energy transfer may be treated as a Markov process.
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Affiliation(s)
- H Grajek
- Department of Physics and Biophysics, University of Agriculture and Technology, Olsztyn, Poland
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Checcucci G, Lenci F, Ghetti F, Song PS. A videomicroscopic study of the effect of a singlet oxygen quencher on Blepharisma Japonicum photobehavior. JOURNAL OF PHOTOCHEMISTRY AND PHOTOBIOLOGY B-BIOLOGY 1991. [DOI: 10.1016/1011-1344(91)80267-l] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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Mulisch M. Ultrastructure and membrane topography of special ciliary organelles in the ciliate Eufolliculina uhligi (Protozoa). Cell Tissue Res 1991. [DOI: 10.1007/bf00318148] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
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Song PS, Kim IH, Florell S, Tamai N, Yamazaki T, Yamazaki I. Structure and function of the photoreceptor stentorins in Stentor coeruleus. II. Primary photoprocess and picosecond time-resolved fluorescence. BIOCHIMICA ET BIOPHYSICA ACTA 1990; 1040:58-65. [PMID: 2378902 DOI: 10.1016/0167-4838(90)90145-6] [Citation(s) in RCA: 25] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Stentorin serves as the photoreceptor for the photophobic and negative phototactic responses in Stentor coeruleus. Two forms of the stentorin have been isolated and purified. The strongly fluorescent form, stentorin I at pH 7.8, exhibited nearly exponential fluorescence decay monitored at 620 nm, having two comparable lifetime decay components of 2.53 ns (47%) and 5.95 ns (53%). Stentorin I showed no significant time-resolved fluorescence emission spectra in the picosecond-nanosecond time scales. The weakly fluorescent form, stentorin II, exhibited an ultrafast fluorescence decay component (10 ps) at an emission wavelength of 630 nm and pH 7.8. The amplitudes of the multi-component fluorescence in stentorin II were found to be emission wavelength-dependent. Furthermore, the fluorescence emission spectrum was time-resolvable in the picosecond time scales. Effects of pH and pD on the fluorescence decay kinetics and time-resolved spectra of stentorins I and II have also been investigated. Results are suggestive of proton dissociation as a primary photoprocess from the excited state of stentorin II.
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Affiliation(s)
- P S Song
- Department of Chemistry, University of Nebraska, Lincoln 68588-0304
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Kim IH, Rhee JS, Huh JW, Florell S, Faure B, Lee KW, Kahsai T, Song PS, Tamai N, Yamazaki T. Structure and function of the photoreceptor stentorins in Stentor coeruleus. I. Partial characterization of the photoreceptor organelle and stentorins. BIOCHIMICA ET BIOPHYSICA ACTA 1990; 1040:43-57. [PMID: 2378901 DOI: 10.1016/0167-4838(90)90144-5] [Citation(s) in RCA: 28] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
The unicellular ciliary protozoan, Stentor coeruleus, exhibits photophobic and phototactic responses to visible light stimuli. The pigment granule contains the photoreceptor chromoproteins (stentorins). Stentorin localized in the pigment granules of the cell serves as the primary photoreceptor for the photophobic and phototactic responses in this organism. An initial characterization of the pigment granules has been described in terms of size, absorbance spectra and ATPase activity. Two forms of the stentorin pigments have been isolated from the pigment granules. Stentorin I has an apparent molecular weight of 68,600 and 52,000 by SDS-PAGE (at 10 and 13% gel, respectively) or 102,000 by steric exclusion HPLC, whereas stentorin II is a larger molecular assembly probably composed of several proteins (mol. wt. greater than 500,000). Stentorin I is composed of at least two heterologous subunits corresponding to apparent mol. wts. of 46,000 (fluorescent, Coomassie blue negative) and 52,000 (fluorescent, Coomassie blue positive) on SDS-PAGE (13% gel). However, these values were found to be strongly dependent on the degree of crosslinking in the acrylamide gel. Stentorin II appears to be the primary photoreceptor whose absorption and fluorescence properties are consistent with the action spectra for the photoresponses of the ciliate to visible light.
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Affiliation(s)
- I H Kim
- Department of Chemistry, University of Nebraska, Lincoln 68588-0304
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Colombetti G. New trends in photobiology. JOURNAL OF PHOTOCHEMISTRY AND PHOTOBIOLOGY B-BIOLOGY 1990. [DOI: 10.1016/1011-1344(90)85031-q] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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Nakaoka Y. Localization of photosensitivity inParamecium bursaria. J Comp Physiol A Neuroethol Sens Neural Behav Physiol 1989. [DOI: 10.1007/bf00610995] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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Song PS. The molecular topography of phytochrome: chromophore and apoprotein. JOURNAL OF PHOTOCHEMISTRY AND PHOTOBIOLOGY. B, BIOLOGY 1988; 2:43-57. [PMID: 3149301 DOI: 10.1016/1011-1344(88)85036-x] [Citation(s) in RCA: 23] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
Phytochrome serves as the photochromic receptor for a number of morphogenic and developmental responses to red light in higher plants. The photoreversible phototransformation of 124 kDa oat phytochrome involves several structural changes in the chromophore and the apoprotein, including a configurational/conformational isomerization and secondary/tertiary structural changes respectively. For example, there appears to be a specific interaction between the chromophore and the amino terminus segment in the Pfr form of phytochrome, which results in a photoreversible peptide folding of the amino terminus peptide chain. Other structural changes also accompany the phototransformation, as has been probed by peptide mapping, phosphorylation, and monoclonal antibodies.
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Affiliation(s)
- P S Song
- Department of Chemistry, School of Biological Sciences, University of Nebraska, Lincoln 68588-0304
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Scevoli P, Bisi F, Colombetti G, Ghetti F, Lenci F, Passarelli V. Photomotile responses of Blepharisma japonicum I: Action spectra determination and time-resolved fluorescence of photoreceptor pigments. JOURNAL OF PHOTOCHEMISTRY AND PHOTOBIOLOGY B-BIOLOGY 1987. [DOI: 10.1016/1011-1344(87)80007-6] [Citation(s) in RCA: 58] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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28
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Chai YG, Song PS, Cordonnier MM, Pratt LH. A photoreversible circular dichroism spectral change in oat phytochrome is suppressed by a monoclonal antibody that binds near its N-terminus and by chromophore modification. Biochemistry 1987; 26:4947-52. [PMID: 3663636 DOI: 10.1021/bi00390a010] [Citation(s) in RCA: 35] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
Accompanying the phototransformation of native 124-kilodalton (kDa) oat phytochrome from red-absorbing form (Pr) to far-red-absorbing form (Pfr), there is a photoreversible change in circular dichroism (CD) in the far-UV region indicative of a 3% increase in alpha-helical folding of apoprotein. To elucidate the conformational change involved in the phytochrome phototransformation, several monoclonal antibodies have been used as epitope-specific probes. Monoclonal antibody oat-25 suppressed the photoreversible CD spectral change using phytochrome with an A666/A280 as Pr of 1.13. Monoclonal antibodies oat-22, oat-13, and oat-31 did not significantly affect the CD spectral change of phytochrome. Oat-25 requires an epitope near the N-terminus of phytochrome. Oat-22, oat-13, and oat-31 recognize epitopes on the N-terminus, chromophore-containing half of phytochrome, albeit further removed from the N-terminus than that recognized by oat-25. Interestingly, oat-13 and oat-31 did, however, induce a time-dependent decrease in the far-UV CD, apparently due to aggregation of phytochrome (both Pr and Pfr forms). Monoclonal antibodies oat-26 and oat-28, which recognize epitopes on the C-terminus half of phytochrome, also did not suppress the photoreversible CD change, although oat-26 and oat-28 slightly inhibited it. The photoreversible CD spectral change can also be inhibited by sodium borohydride, which bleaches the chromophore by reducing it, and by tetranitromethane, which oxidizes the chromophore of phytochrome. Although explanations of these results based on indirect interactions between the chromophore and the N-terminus segment are possible, we propose that an additional alpha-helical folding of the Pfr form of the phytochrome may result from a photoreversible interaction between the Pfr form of the chromophore and the N-terminus segment.
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Affiliation(s)
- Y G Chai
- Department of Chemistry and Biochemistry, Texas Tech University, Lubbock 79409
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Vierstra RD, Quail PH, Hahn TR, Song PS. Comparison of the protein conformations between different forms (Pr and Pfr) of native (124 kDa) and degraded (118/114 kDa) phytochromes from Avena sativa. Photochem Photobiol 1987; 45:429-32. [PMID: 3562595 DOI: 10.1111/j.1751-1097.1987.tb05398.x] [Citation(s) in RCA: 31] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
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Whitfield JF, Durkin JP, Franks DJ, Kleine LP, Raptis L, Rixon RH, Sikorska M, Walker PR. Calcium, cyclic AMP and protein kinase C--partners in mitogenesis. Cancer Metastasis Rev 1987; 5:205-50. [PMID: 3030578 DOI: 10.1007/bf00046999] [Citation(s) in RCA: 75] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
Evidence is steadily mounting that the proto-oncogenes, whose products organize and start the programs that drive normal eukaryotic cells through their chromosome replication/mitosis cycles, are transiently stimulated by sequential signals from a multi-purpose, receptor-operated mechanism (consisting of internal surges of Ca2+ and bursts of protein kinase C activity resulting from phosphatidylinositol 4,5-bisphosphate breakdown and the opening of membrane Ca2+ channels induced by receptor-associated tyrosine-protein kinase activity) and bursts of cyclic AMP-dependent kinase activity. The bypassing or subversion of the receptor-operated Ca2+/phospholipid breakdown/protein kinase C signalling mechanism is probably the basis of the freeing of cell proliferation from external controls that characterizes all neoplastic transformations.
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Yang KC, Prusti RK, Walker EB, Song PS, Watanabe M, Furuya M. Photodynamic action in Stentor coeruleus sensitized by endogenous pigment stentorin. Photochem Photobiol 1986; 43:305-10. [PMID: 3085113 DOI: 10.1111/j.1751-1097.1986.tb05609.x] [Citation(s) in RCA: 42] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
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Sharrock RA, Lissemore JL, Quail PH. Nucleotide and amino acid sequence of a Cucurbita phytochrome cDNA clone: identification of conserved features by comparison with Avena phytochrome. Gene X 1986; 47:287-95. [PMID: 3557123 DOI: 10.1016/0378-1119(86)90072-7] [Citation(s) in RCA: 44] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023] Open
Abstract
The amino acid (aa) sequence of Cucurbita phytochrome has been deduced from the nucleotide (nt) sequence of a cDNA clone which was initially identified by hybridization to an Avena phytochrome cDNA clone. Cucurbita, a dicot, and Avena, a monocot, represent evolutionarily divergent groups of plants. The Cucurbita phytochrome polypeptide is 1123 aa in length, corresponding to 125 kDa. Overall, the Cucurbita and Avena phytochrome sequences are 65% homologous at both the nt and aa levels but this sequence conservation is not evenly distributed. Most of the N-terminal two-thirds of the aligned polypeptide chains exhibits localized regions of high conservation, while the extreme N terminus and the C-terminal one-third are less homologous. Comparison of the predicted hydropathic properties of these polypeptides also indicates conservation of domains of phytochrome structure. The possible correlation of these conserved structural features with previously identified functional domains of phytochrome is discussed.
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Hershey HP, Barker RF, Idler KB, Lissemore JL, Quail PH. Analysis of cloned cDNA and genomic sequences for phytochrome: complete amino acid sequences for two gene products expressed in etiolated Avena. Nucleic Acids Res 1985; 13:8543-59. [PMID: 3001642 PMCID: PMC322151 DOI: 10.1093/nar/13.23.8543] [Citation(s) in RCA: 131] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023] Open
Abstract
Cloned cDNA and genomic sequences have been analyzed to deduce the amino acid sequence of phytochrome from etiolated Avena. Restriction endonuclease site polymorphism between clones indicates that at least four phytochrome genes are expressed in this tissue. Sequence analysis of two complete and one partial coding region shows approximately 98% homology at both the nucleotide and amino acid levels, with the majority of amino acid changes being conservative. High sequence homology is also found in the 5'-untranslated region but significant divergence occurs in the 3'-untranslated region. The phytochrome polypeptides are 1128 amino acid residues long corresponding to a molecular mass of 125 kdaltons. The known protein sequence at the chromophore attachment site occurs only once in the polypeptide, establishing that phytochrome has a single chromophore per monomer covalently linked to Cys-321. Computer analyses of the amino acid sequences have provided predictions regarding a number of structural features of the phytochrome molecule.
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Köhler K, Steigner W, Simonis W, Urbach W. Potassium channels in Eremosphaera viridis : I. Influence of cations and pH on resting membrane potential and on an action-potential-like response. PLANTA 1985; 166:490-499. [PMID: 24241614 DOI: 10.1007/bf00391273] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/19/1985] [Accepted: 05/24/1985] [Indexed: 06/02/2023]
Abstract
The dependence of the membrane potential of Eremosphaera viridis on different external concentrations of potassium, sodium, calcium, and protons was compared with the diffusion potential measured in the dark and in the presence of NaN3. In contrast to some other algae, the membrane potential in the light as well as in the dark seemed to be predominantly determined by the calculated diffusion potential and less by an electrogenic pump which, however, seemed to be involved at potassium concentrations >1 mol·m(-3) and at higher pHos (>pH 6). Furthermore, some characteristics of an action-potential-like response (CAP) triggered by light-off, and independent of the membrane-potential threshold value, were determined. The CAP had a delay period of 5.4 s and needed 4.5 s for polarization to a plateau. On average, the plateau held for 8.8 s and the CAP lasted 37.7 s. The peak amplitudes of CAP (P AP) exactly followed the Nernst potential of potassium. Other cations like sodium, calcium and protons did not appreciably affect the peak amplitudes of CAP. From these and other results it can be assumed that the CAP is caused by a temporary opening of potassium channels in the plasma membrane of Eremosphaera (Köhler et al., 1983, Planta 159, 165-171). The release of a CAP by light-off has been partly explained by the participation of a transient increase of proton concentration in the cytoplasm. It was possible to trigger a CAP by external pH changes and by the addition of sodium acetate, thus supporting the hypothesis that a pH decrease in the cytoplasm may be one element of the signal transfer from the photosynthetic system to the potassium channels in the plasmalemma. Calcium also seemed to have an influence on triggering the CAP.
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Affiliation(s)
- K Köhler
- Lehrstuhl Botanik I der Universität, Mittlerer Dallenbergweg 64, D-8700, Würzburg, Federal Republic of Germany
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Yatsuhashi H, Kadota A, Wada M. Blue- and red-light action in photoorientation of chloroplasts in Adiantum protonemata. PLANTA 1985; 165:43-50. [PMID: 24240956 DOI: 10.1007/bf00392210] [Citation(s) in RCA: 44] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/10/1984] [Accepted: 01/30/1985] [Indexed: 06/02/2023]
Abstract
An action spectrum for the low-fluencerate response of chloroplast movement in protonemata of the fern Adiantum capillus-veneris L. was determined using polarized light vibrating perpendicularly to the protonema axis. The spectrum had several peaks in the blue region around 450 nm and one in the red region at 680 nm, the blue peaks being higher than the red one. The red-light action was suppressed by nonpolarized far-red light given simultaneously or alternately, whereas the bluelight action was not. Chloroplast movement was also induced by a local irradiation with a narrow beam of monochromatic light. A beam of blue light at low energy fluence rates (7.3·10(-3)-1.0 W m(-2)) caused movement of the chloroplasts to the beam area (positive response), while one at high fluence rates (10 W m(-2) and higher) caused movement to outside of the beam area (negative response). A red beam caused a positive response at fluence rates up to 100 W m(-2), but a negative response at very high fluence rates (230 and 470 W m(-2)). When a far-red beam was combined with total background irradiation with red light at fluence rates causing a low-fluence-rate response in whole cells, chloroplasts moved out of the beam area. When blue light was used as background irradiation, however, a narrow far-red beam had no effect on chloroplast distribution. These results indicate that the light-oriented movement of Adiantum chloroplasts is caused by red and blue light, mediated by phytochrome and another, unidentified photoreceptor(s), respectively. This movement depends on a local gradient of the far-red-absorbing form of phytochrome or of a photoexcited blue-light photoreceptor, and it includes positive and negative responses for both red and blue light.
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Affiliation(s)
- H Yatsuhashi
- Department of Biology, Tokyo Metropolitan University, Fukazawa, 158, Setagayaku, Tokyo, Japan
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Prusti RK, Song PS, Häder DP, Häder M. Caffeine-enhanced photomovement in the ciliate, Stentor coeruleus. Photochem Photobiol 1984; 40:369-75. [PMID: 6435141 DOI: 10.1111/j.1751-1097.1984.tb04600.x] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
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