Characterization and Expression of the Gene Encoding En-MAPK1, an Intestinal Cell Kinase (ICK)-like Kinase Activated by the Autocrine Pheromone-Signaling Loop in the Polar Ciliate, Euplotes nobilii

• Published in: International Journal of Molecular Sciences
• Main Authors: Candelori, Annalisa, Luporini, Pierangelo, Alimenti, Claudio, Vallesi, Adriana
• Format: Text
• Language: English
• Published: Molecular Diversity Preservation International (MDPI) 2013
• Subjects: Article; Antarctic; Arctic; Antarc*
• Online Access: http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3645696; http://www.ncbi.nlm.nih.gov/pubmed/23552830; https://doi.org/10.3390/ijms14047457

In the protozoan ciliate Euplotes, a transduction pathway resulting in a mitogenic cell growth response is activated by autocrine receptor binding of cell type-specific, water-borne signaling protein pheromones. In Euplotes raikovi, a marine species of temperate waters, this transduction pathway was previously shown to involve the phosphorylation of a nuclear protein kinase structurally similar to the intestinal-cell and male germ cell-associated kinases described in mammals. In E. nobilii, which is phylogenetically closely related to E. raikovi but inhabits Antarctic and Arctic waters, we have now characterized a gene encoding a structurally homologous kinase. The expression of this gene requires +1 translational frameshifting and a process of intron splicing for the production of the active protein, designated En-MAPK1, which contains amino acid substitutions of potential significance for cold-adaptation.