Calcineurin Silencing in Dictyostelium discoideum Leads to Cellular Alterations Affecting Mitochondria, Gene Expression, and Oxidative Stress Response

Publication date: August 2018Source: Protist, Volume 169, Issue 4Author(s): Konstanze Kobel-Höller, Kevin Gley, Janina Jochinke, Kristina Heider, Verena Nadin Fritsch, Ha Viet Duc Nguyen, Timo Lischke, Renate Radek, Ria Baumgrass, Rupert Mutzel, Sascha ThewesCalcineurin is involved in development and cell differentiation of the social amoeba Dictyostelium discoideum. However, since knockouts of the calcineurin-encoding genes are not possible in D. discoideum it is assumed that the phosphatase also plays a crucial role during vegetative growth of the amoebae. Therefore, we investigated the role of calcineurin during vegetative growth in D. discoideum. RNAi-silenced calcineurin mutants showed cellular alterations with an abnormal morphology of mitochondria and had increased content of mitochondrial DNA (mtDNA). In contrast, mitochondria showed no substantial functional impairment. Calcineurin-silencing led to altered expression of calcium-regulated genes as well as mitochondrially-encoded genes. Furthermore, genes related to oxidative stress were higher expressed in the mutants, which correlated to an increased resistance towards reactive oxygen species (ROS). Most of the changes observed during vegetative growth were not seen after starvation of the calcineurin mutants. We show that impairment of calcineurin led to many subtle, but in the sum crucial cellular alterations in vegetative D. discoideum cells. As these alterations were not observed after starvation we propose a du...
Source: Protist - Category: Molecular Biology Source Type: research