Molecular characterization of a calmodulin involved in the signal transduction chain of gravitaxis in Euglena gracilis

Daiker, Viktor; Lebert, Michael; Richter, Peter; Häder, Donat-Peter

doi:10.1007/s00425-010-1126-9

Cited by 26 publications

(24 citation statements)

References 22 publications

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“…7.6). This is not consistent with Daiker et al (2010), who found the presence of five calmodulins (CaM.1-5) in E. gracilis. The absence of CaM.1-7 from the genome assembly is likely due to incompleteness.…”

Section: The Tubulin and Calmodulin Genescontrasting

confidence: 68%

“…11, this volume), oxygen pressure, gravity (gravitaxis, see Chap. 12, this volume) (Porterfield 1997;Streb et al 2002;Hader et al 2005a, b;Daiker et al 2010), and signal transduction (Daiker et al 2010). Calmodulin and protein kinases are involved in gravitaxis (Streb et al 2002).Five types of CaM proteins have been discovered in E. gracilis and include: CaM.1, CaM.2, CaM.3, CaM.4, and CaM.5, with CaM.2 being implicated in gravitaxis (Toda et al 1992;Daiker et al 2010).…”

Section: The Tubulin and Calmodulin Genesmentioning

confidence: 96%

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Euglena gracilis Genome and Transcriptome: Organelles, Nuclear Genome Assembly Strategies and Initial Features

Ebenezer

Carrington

Lebert

et al. 2017

Advances in Experimental Medicine and Biology

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Euglena gracilis is a major component of the aquatic ecosystem and together with closely related species, is ubiquitous worldwide. Euglenoids are an important group of protists, possessing a secondarily acquired plastid and are relatives to the Kinetoplastidae, which themselves have global impact as disease agents. To understand the biology of E. gracilis, as well as to provide further insight into the evolution and origins of the Kinetoplastidae, we embarked on sequencing the nuclear genome; the plastid and mitochondrial genomes are already in the public domain. Earlier studies suggested an extensive nuclear DNA content, with likely a high degree of repetitive sequence, together with significant extrachromosomal elements. To produce a list of coding sequences we have combined transcriptome data from both published and new sources, as well as embarked on de novo sequencing using a combination of 454, Illumina paired end libraries and long PacBio reads. Preliminary analysis suggests a surprisingly large genome approaching 2 Gbp, with a highly fragmented architecture and extensive repeat composition. Over 80% of the RNAseq reads from E. gracilis maps to the assembled genome sequence, which is comparable with the well assembled genomes of T. brucei and T. cruzi. In order to achieve this level of assembly we employed multiple informatics pipelines, which are discussed here. Finally, as a preliminary view of the genome architecture, we discuss the tubulin and calmodulin genes, which highlight potential novel splicing mechanisms.

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Section: The Tubulin and Calmodulin Genescontrasting

confidence: 68%

Section: The Tubulin and Calmodulin Genesmentioning

confidence: 96%

Euglena gracilis Genome and Transcriptome: Organelles, Nuclear Genome Assembly Strategies and Initial Features

Ebenezer

Carrington

Lebert

et al. 2017

Advances in Experimental Medicine and Biology

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“…These membrane proteins could allow an ion transport when activated which in some cases has been found to consist of calcium ions. At least in the case of Euglena the gated calcium activates calmodulin, 32, 113 which is a universal regulatory protein in many prokaryotic and eukaryotic taxa. 36, 114 The influx of Ca 2+ changes the membrane potential as has been found in ciliates and flagellates, which might be a subsequent step in the sensory transduction chain being responsible for signal amplification.…”

Section: Introductionmentioning

confidence: 99%

Gravireceptors in eukaryotes—a comparison of case studies on the cellular level

et al. 2017

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We have selected five evolutionary very different biological systems ranging from unicellular protists via algae and higher plants to human cells showing responses to the gravity vector of the Earth in order to compare their graviperception mechanisms. All these systems use a mass, which may either by a heavy statolith or the whole content of the cell heavier than the surrounding medium to operate on a gravireceptor either by exerting pressure or by pulling on a cytoskeletal element. In many cases the receptor seems to be a mechanosensitive ion channel activated by the gravitational force which allows a gated ion flux across the membrane when activated. This has been identified in many systems to be a calcium current, which in turn activates subsequent elements of the sensory transduction chain, such as calmodulin, which in turn results in the activation of ubiquitous enzymes, gene expression activation or silencing. Naturally, the subsequent responses to the gravity stimulus differ widely between the systems ranging from orientational movement and directed growth to physiological reactions and adaptation to the environmental conditions.

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“…However, some elements of the downstream signalling cascade have recently been validated through RNA interference, such as presence of calmodulin (Daiker et al . ) and protein kinase A (Daiker et al . ).…”

Section: Introductionmentioning

confidence: 99%

The influence of microgravity on Euglena gracilis as studied on Shenzhou 8

et al. 2013

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The German Aerospace Center (DLR) enabled German participation in the joint space campaign on the unmanned Shenzhou 8 spacecraft in November 2011. In this report, the effect of microgravity on Euglena gracilis cells is described. Custom-made dual compartment cell fixation units (containing cells in one chamber and fixative - RNA lysis buffer - in another one) were enclosed in a small container and placed in the Simbox incubator, which is an experiment support system. Cells were fixed by injecting them with fixative at different time intervals. In addition to stationary experiment slots, Simbox provides a 1 g reference centrifuge. Cell fixation units were mounted in microgravity and 1 g reference positions of Simbox. Two Simbox incubators were used, one for space flight and the other as ground reference. Cells were fixed soon after launch and shortly before return of the spaceship. Due to technical problems, only early in-flight samples (about 40 min after launch microgravity and corresponding 1 g reference) were fully mixed with fixative, therefore only data from those samples are presented. Transcription of several genes involved in signal transduction, oxidative stress defence, cell cycle regulation and heat shock responses was investigated with quantitative PCR. The data indicate that Euglena cells suffer stress upon short-term exposure to microgravity; various stress-induced genes were up-regulated. Of 32 tested genes, 18 were up-regulated, one down-regulated and the rest remained unaltered. These findings are in a good agreement with results from other research groups using other organisms.

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Molecular characterization of a calmodulin involved in the signal transduction chain of gravitaxis in Euglena gracilis

Cited by 26 publications

References 22 publications

Euglena gracilis Genome and Transcriptome: Organelles, Nuclear Genome Assembly Strategies and Initial Features

Euglena gracilis Genome and Transcriptome: Organelles, Nuclear Genome Assembly Strategies and Initial Features

Gravireceptors in eukaryotes—a comparison of case studies on the cellular level

The influence of microgravity on Euglena gracilis as studied on Shenzhou 8

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