The water-borne protein signals (pheromones) of the Antarctic ciliated protozoan Euplotes nobilii : structure of the gene coding for the E n -6 pheromoneThis article is one of a selection of papers in the Special Issue on Polar and Alpine Microbiology.

The marine Antarctic ciliate, Euplotes nobilii , secretes a family of water-borne signal proteins, denoted as pheromones, which control vegetative proliferation and mating in the cell. Based on the knowledge of the amino acid sequences of a set of these pheromones isolated from the culture supernata...

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Bibliographic Details
Published in:Canadian Journal of Microbiology
Main Authors: La Terza, Antonietta, Dobri, Nicoleta, Alimenti, Claudio, Vallesi, Adriana, Luporini, Pierangelo
Format: Article in Journal/Newspaper
Language:English
Published: Canadian Science Publishing 2009
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Online Access:http://dx.doi.org/10.1139/w08-122
http://www.nrcresearchpress.com/doi/full-xml/10.1139/W08-122
http://www.nrcresearchpress.com/doi/pdf/10.1139/W08-122
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Summary:The marine Antarctic ciliate, Euplotes nobilii , secretes a family of water-borne signal proteins, denoted as pheromones, which control vegetative proliferation and mating in the cell. Based on the knowledge of the amino acid sequences of a set of these pheromones isolated from the culture supernatant of wild-type strains, we designed probes to identify their encoding genes in the cell somatic nucleus (macronucleus). The full-length gene of the pheromone En-6 was determined and found to contain an open-reading frame specific for the synthesis of the En-6 cytoplasmic precursor (pre-pro-En-6), which requires 2 proteolytic cleavages to remove the signal peptide (pre) and the prosegment before secretion of the mature protein. In contrast to the sequence variability that distinguishes the secreted pheromones, the pre- and pro-sequences appear to be tightly conserved and useful for the construction of probes to clone every other E. nobilii pheromone gene. Potential intron sequences in the coding region of the En-6 gene imply the synthesis of more En-6 isoforms.