Disruption of a Dynamin Homologue Affects Endocytosis, Organelle Morphology, and Cytokinesis inDictyostelium discoideum

Abstract

The identification and functional characterization of Dictyostelium discoideum dynamin A, a protein composed of 853 amino acids that shares up to 44% sequence identity with other dynamin-related proteins, is described. Dynamin A is present during all stages of D. discoideum development and is found predominantly in the cytosolic fraction and in association with endosomal and postlysosomal vacuoles. Overexpression of the protein has no adverse effect on the cells, whereas depletion of dynamin A by gene-targeting techniques leads to multiple and complex phenotypic changes. Cells lacking a functional copy of dymA show alterations of mitochondrial, nuclear, and endosomal morphology and a defect in fluid-phase uptake. They also become multinucleated due to a failure to complete normal cytokinesis. These pleiotropic effects of dynamin A depletion can be rescued by complementation with the cloned gene. Morphological studies using cells producing green fluorescent protein-dynamin A revealed that dynamin A associates with punctate cytoplasmic vesicles. Double labeling with vacuolin, a marker of a postlysosomal compartment in D. discoideum, showed an almost complete colocalization of vacuolin and dynamin A. Our results suggest that that dynamin A is likely to function in membrane trafficking processes along the endo-lysosomal pathway of D. discoideum but not at the plasma membrane.

Evolutionary linkage between eukaryotic cytokinesis and chloroplast division by dynamin proteins

“…To date, certain members of the dynamin family have been shown to be involved in cytokinesis (23,24,29,30). In the phylogenetic tree, these proteins (members separately grouped in yellow and gray, DymA of D. discoideum in the mitochondrial division clade in Fig.…”

Cytokinesis in Animal Cells

“…Cite this article as Cold Spring Harb Perspect Biol 2015;7:a015834 Mutations in genes encoding endocytic components, such as clathrin and dynamin, were shown to disrupt cytokinesis in several animal models and mammalian cells (Wienke et al 1999;Gerald et al 2001;Thompson et al 2002). Three small GTPases that regulate recycling trafficking, Rab11, Arf6, and Rab35, are required for completion of cytokinesis in a variety of cell types (Montagnac et al 2008;Schiel and Prekeris 2013).…”

Contractile Ring-independent Localization of DdINCENP, a Protein Important for Spindle Stability and Cytokinesis

“…Several membrane-trafficking proteins have been shown to be required late in cytokinesis including dynamin, clathrin, LvsA, syntaxin, rabs, and others (O'Halloran, 2000). Interestingly, the depletion of dynamin in Dictyostelium cause a very similar late cytokinesis defect because the daughter cells were often connected by a thin cytoplasmic bridge for prolonged period (Wienke et al, 1999).…”