The Photobiology of Blepharisma

Giese, Arthur C.

doi:10.1007/978-1-4684-7003-1_4

Cited by 41 publications

(16 citation statements)

References 51 publications

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“…Pigment granules of B. japonicum contain five different red pigments, called blepharismins, recently chemically synthesised and structurally related to two well known photodynamic and toxic pigments: hypericin, extracted from the plant Hypericum, and stentorin, extracted from the ciliate S. coeruleus (Cameron & Riches, 1995;Dai et al, 1995;Yoshioka et al, 2008). To date, the three main functions that have been ascribed to blepharismins are photoreception, chemical defence against predators and protection against UV radiation (Giese, 1981;Miyake et al, 1990;Harumoto et al, 1998). In addition to physiological functions, blepharismins were also demonstrated to exert an antibiotic effect against the Gram-positive bacterium Staphylococcus aureus (Pant et al, 1997).…”

Section: Introductionmentioning

confidence: 99%

Chemical defence by mono-prenyl hydroquinone in a freshwater ciliate, Spirostomum ambiguum

et al. 2011

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Several species of ciliates produce and accumulate low molecular weight toxic compounds in specialised membrane-bound ejectable organelles: extrusomes. These compounds can be used in predator–prey interaction for killing prey as well as for chemical defence. Here, we describe the isolation and characterisation of 2-(3-methylbut-2-enyl)benzene-1,4-diol(mono-prenyl hydroquinone), the extrusomal defensive toxin of the freshwater heterotrich ciliate Spirostomum ambiguum. The toxin was purified at homogeneity by RP-HPLC, and its structural characterisation was carried out through NMR and MS measurements. In vivo experiments involving S. ambiguum and Climacostomum virens in predator–prey interaction, and the analysis of cytotoxic activity of mono-prenyl hydroquinone on a panel of free-living freshwater ciliates, indicated that the toxin is very effective in S. ambiguum’s chemical defence

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Section: Introductionmentioning

confidence: 99%

Chemical defence by mono-prenyl hydroquinone in a freshwater ciliate, Spirostomum ambiguum

et al. 2011

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“…Hypericin-like pigments are present in the protozoa Blepharisma and Stentor (Giese, 1980a,b;1981) and in Fagopyrum esculentum (Wender et Brockmann, 1947Brockmann, ,1952Metzner, 1958;Bwangamol, 1967;Giese, 1972).…”

Section: Introductionmentioning

confidence: 99%

Hypericin and Its Photodynamic Action

Durán

Song

1986

Photochem & Photobiology

270

171

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“…The ciliary reversal observed during photophobic response is mediated by a membrane action potential, which can be elicited by an early light-induced depolarizing receptor potential (Fabczak et al, 1993). So far, the cell photosensitivity has been ascribed to its endogenous photoreceptor systems, composed of numerous pigment granules located beneath the plasma membrane (Giese, 1981;Matsuoka, 1983). Each granule contains the hipericin-like pigment blepharismin, which is thought to function as the primary photoreceptor eliciting the cell photoresponses (Tao et al, 1994;Song, 1997;Maeda et al, 1997;Matsuoka et al, 1997;Matsuoka et al, 2000).…”

Section: Introductionmentioning

confidence: 99%

Phosducin interacts with the G-protein βγ-dimer of ciliate protozoanBlepharisma japonicumupon illumination

Sobierajska

Fabczak

2007

Journal of Experimental Biology

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SUMMARY Immunological techniques and high-resolution FRET analysis were employed to investigate the in vivo colocalization and interaction of phosducin(Pdc) with the βγ-subunits of G-protein (Gβγ) in the ciliate Blepharisma japonicum. Immunological techniques revealed that illumination of cells resulted in a decrease in phosphorylation levels of Pdc and its colocalization with Gβγ. The observed light-induced Pdc dephosphorylation was also accompanied by significant enhancement of Gβγ binding by this molecule. Possible formation of the Pdc–Gβγ complex in cells exposed to light was corroborated by FRET between these proteins. Treatment of cells with okadaic acid, an inhibitor of phosphatase activity, entirely prevented Pdc dephosphorylation by light, colocalization of this phosphoprotein with Gβγ and generation of the Pdc–Gβγ complex. Cell fractionation and immunoblotting revealed that in cells exposed to light, the formation of Pdc–Gβγ complex and its translocation into the cytoplasm occur simultaneously with a change in the gel migration of Gβ. Moreover, a 33 kDa immunoanalog of 14-3-3 protein was identified and we showed that this protein is bound by phosphorylated Pdc in a cell adapted to darkness. The results of this study provide additional detailed characterization of the functional properties of the ciliate Pdc. The likely functional role of Pdc in Blepharisma is discussed.

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The Photobiology of Blepharisma

Cited by 41 publications

References 51 publications

Chemical defence by mono-prenyl hydroquinone in a freshwater ciliate, Spirostomum ambiguum

Chemical defence by mono-prenyl hydroquinone in a freshwater ciliate, Spirostomum ambiguum

Hypericin and Its Photodynamic Action

Phosducin interacts with the G-protein βγ-dimer of ciliate protozoanBlepharisma japonicumupon illumination

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