Stress-dependent Transcription of a Gene Encoding a Gβ-like Polypeptide from Chlamydomonas reinhardtii

Kampen, Jan von; Nieländer, Ute; Wettern, Michael

doi:10.1016/s0176-1617(11)81171-5

Cited by 32 publications

(34 citation statements)

References 13 publications

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“…In general, knowledge about G protein function and the subgroups present in plants is still very limited, although different Ga-and Gfl-like proteins have already been identified in higher plants (for reviews see Terryn et al, 1993;Ma, 1994) and C. reinhardtii (Schloss, 1990;Von Kampen et al, 1994).…”

Section: Discussionmentioning

confidence: 99%

G proteins and Ca²⁺-modulated protein kinases of a plasma membrane-enriched fraction and isolated eyespot apparatuses ofSpermatozopsis similis(chlorophyceae)

Schlicher¹,

Lindén²,

Calenberg³

et al. 1995

European Journal of Phycology

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Knowledge about possible elements involved in signal transduction and adaptational phenomena during phototaxis of flagellate green algae is limited. In order to identify such putative elements we present here: (i) the isolation and characterisation of an enriched plasma membrane fraction of Spermatozopsis similis, and (ii) a comparison of the distribution of Ca2+-dependent putative kinases and G proteins, as recognised by antibodies directed against mammalian Gc~-subunits, in the plasma membrane preparation and isolated eyespot apparatuses of this green alga. In western blot analyses a 54 kDa protein reacted with an antiserum against a conserved sequence of G protein c~-subunits (anti-c~ common). A 43 kDa protein was recognised by a serum against the G~-subunit of transducin. These proteins were enriched in the eyespot fraction and to a lesser extent in the plasma membrane fraction. Two polyclonal antisera against C-terminal peptides of animal G(~-subunits also labelled a 43 kDa and 54 kDa protein in the eyespot preparations. Additionally, four putative Ca2+-dependent kinases or their catalytic subunits (47, 48, 77 and 82 kDa) were identified in the plasma membrane fraction by a gel kinase assay following electrophoretic separation. The 82 kDa protein was specifically enriched in the plasma membrane fraction, while the other putative kinases were also enriched in the eyespot fraction but not in other subcellutar fractions. Monoclonal antibodies directed against a soybean CaZ+-dependent protein kinase cross-reacted with a 6I kDa protein in the plasma membrane and a 60 kDa protein in the soluble fraction. Only a very faint response was observed in the fraction enriched in eyespot apparatuses. Our results indicate (i) a low cross-contamination of the eyespot apparatus preparation by normal plasma membrane constituents and (ii) the regulatory potential for the identified kinases and G proteins in blue/green-light-dependent photoresponses of Spermatozopsis similis.

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Section: Discussionmentioning

confidence: 99%

G proteins and Ca²⁺-modulated protein kinases of a plasma membrane-enriched fraction and isolated eyespot apparatuses ofSpermatozopsis similis(chlorophyceae)

Schlicher¹,

Lindén²,

Calenberg³

et al. 1995

European Journal of Phycology

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“…The HEMA-specific probe was a 560-bp fragment corresponding to the coding region of HEMA. For a loading control, a 1-kb cDNA fragment of CBLP was employed (56). RNA blots were quantitated using a PhosphorImager (Bio-Rad Laboratories GmbH, Munich, Germany).…”

Section: Methodsmentioning

confidence: 99%

Mg-Protoporphyrin IX and Heme ControlHEMA, the Gene Encoding the First Specific Step of Tetrapyrrole Biosynthesis, inChlamydomonas reinhardtii

Vasileuskaya

Oster²,

Beck

2005

Eukaryot Cell

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HEMA encodes glutamyl-tRNA reductase (GluTR), which catalyzes the first step specific for tetrapyrrole biosynthesis in plants, archaea, and most eubacteria. In higher plants, GluTR is feedback inhibited by heme and intermediates of chlorophyll biosynthesis. It plays a key role in controlling flux through the tetrapyrrole biosynthetic pathway. This enzyme, which in Chlamydomonas reinhardtii is encoded by a single gene (HEMA), exhibits homology to GluTRs of higher plants and cyanobacteria. HEMA mRNA accumulation was inducible not only by light but also by treatment of dark-adapted cells with Mg-protoporphyrin IX (MgProto) or hemin. The specificity of these tetrapyrroles as inducers was demonstrated by the absence of induction observed upon the feeding of protoporphyrin IX, the precursor of both heme and MgProto, or chlorophyllide. The HEMA mRNA accumulation following treatment of cells with light and hemin was accompanied by increased amounts of GluTR. However, the feeding of MgProto did not suggest a role for Mg-tetrapyrroles in posttranscriptional regulation. The induction by light but not that by the tetrapyrroles was prevented by inhibition of cytoplasmic protein synthesis. Since MgProto is synthesized exclusively in plastids and heme is synthesized in plastids and mitochondria, the data suggest a role of these compounds as organellar signals that control expression of the nuclear HEMA gene.

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“…The GLE gene probe (Kinoshita et al, 1992) and the CBLP gene, encoding a Chlamydomonas Gp-like polypeptide (von Kampen et al, 1994), were kindly provided by Dr. Matsuda and Dr. Wettern, respectively.…”

Section: Rna Lsolation and Northern-blot Hybridizationmentioning

confidence: 99%

Characterization of Blue Light Signal Transduction Chains That Control Development and Maintenance of Sexual Competence in Chlamydomonas reinhardtii

1997

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Blue light induces the differentiation of Chlamydomonas reinhardtii pregametes to gametes. The light-induced conversion of pregametes to gametes is protein synthesis dependent and proceeds only after a lag phase. Upon incubation in the dark, gametes lost their mating ability, resulting in dark-inactivated gametes. Reillumination rapidly restored mating competence and this was shown to be independent of protein synthesis. Apparently, differentiation and maintenance of gametic competence are both regulated by light. Whether one or two light-activated signal pathways are involved was investigated using pharmacological compounds that affect signal transduction. Compounds that affected pregamete-togamete conversion affected the expression of a gamete-specific gene in a similar fashion. Other drugs affected only dark-inactivated gametes, suggesting that reactivating gametes requires a separate signaling pathway. Combined treatments provided evidence for the consecutive action of a phosphatase and a protein kinase C-like kinase in the light-induced reactivation process.

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Stress-dependent Transcription of a Gene Encoding a Gβ-like Polypeptide from Chlamydomonas reinhardtii

Cited by 32 publications

References 13 publications

G proteins and Ca²⁺-modulated protein kinases of a plasma membrane-enriched fraction and isolated eyespot apparatuses ofSpermatozopsis similis(chlorophyceae)

G proteins and Ca²⁺-modulated protein kinases of a plasma membrane-enriched fraction and isolated eyespot apparatuses ofSpermatozopsis similis(chlorophyceae)

Mg-Protoporphyrin IX and Heme ControlHEMA, the Gene Encoding the First Specific Step of Tetrapyrrole Biosynthesis, inChlamydomonas reinhardtii

Characterization of Blue Light Signal Transduction Chains That Control Development and Maintenance of Sexual Competence in Chlamydomonas reinhardtii

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Stress-dependent Transcription of a Gene Encoding a Gβ-like Polypeptide from Chlamydomonas reinhardtii

Cited by 32 publications

References 13 publications

G proteins and Ca2+-modulated protein kinases of a plasma membrane-enriched fraction and isolated eyespot apparatuses ofSpermatozopsis similis(chlorophyceae)

G proteins and Ca2+-modulated protein kinases of a plasma membrane-enriched fraction and isolated eyespot apparatuses ofSpermatozopsis similis(chlorophyceae)

Mg-Protoporphyrin IX and Heme ControlHEMA, the Gene Encoding the First Specific Step of Tetrapyrrole Biosynthesis, inChlamydomonas reinhardtii

Characterization of Blue Light Signal Transduction Chains That Control Development and Maintenance of Sexual Competence in Chlamydomonas reinhardtii

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G proteins and Ca²⁺-modulated protein kinases of a plasma membrane-enriched fraction and isolated eyespot apparatuses ofSpermatozopsis similis(chlorophyceae)

G proteins and Ca²⁺-modulated protein kinases of a plasma membrane-enriched fraction and isolated eyespot apparatuses ofSpermatozopsis similis(chlorophyceae)