Actin assembly states in Dictyostelium discoideum at different stages of development and during cellular stress

Abstract

The actin cytoskeleton of non-muscle cells is essential for cellular structure and subcellular organization, and the dynamic regulation of actin assembly and disassembly is a prerequisite for motility. Pioneering work using Dictyostelium discoideum focused on the biochemical analysis of non-muscle actin, the identification of actin-regulating proteins and their specific functions during processes like cell migration, cytokinesis, phagocytosis, and morphogenesis. Although subsequent work in higher eukaryotes revealed that the processes regulating actin dynamics are often much more complex, results obtained by using Dictyostelium have been of fundamental importance because they have contributed significantly to our understanding of the actin cytoskeleton in higher eukaryotes. Dictyostelium is an accepted model system for studying fast moving cells, because the single cells of the organism share many similarities with cells of the immune system such as human neutrophils. Here we provide a brief overview on the milestones of research of the actin cytoskeleton taking advantage of Dictyostelium. Furthermore, we summarize how actin structures and cytoskeletal dynamics at different stages of development have been visualized, and give an overview on the current focus of research. In addition, we discuss results showing actin assembly states during phases of cellular stress and how stress-induced actin assembly states may contribute to our understanding of certain diseases.

Dual regulation of the actin cytoskeleton by CARMIL-GAP

“…Cell coalescence is driven by the migration of cells towards an extracellular gradient of cAMP that is generated initially by a small number of pioneer cells. Individual amoeba initially undergo chemotaxis towards these pioneer cells, but within hours begin to merge in head-to-tail fashion to create large streams of cells moving together towards what has now become a cAMP-emitting aggregation center ( Ishikawa-Ankerhold and Müller-Taubenberger, 2019 ; Nichols et al, 2015 ). Fig.…”

Dual regulation of the actin cytoskeleton by CARMIL-GAP

“…Cell coalescence is driven by the migration of cells towards an extracellular gradient of cAMP that is generated initially by a small number of pioneer cells. Individual amoeba initially chemotaxis towards these pioneer cells, but within hours begin to merge in head-to-tail fashion to create large streams of cells moving together towards what has now become a cAMP-emitting aggregation center (Ishikawa-Ankerhold and Müller-Taubenberger, 2019; Nichols et al, 2015). Figure 6, column 1, shows a representative “streaming assay” for WT cells, where large streams had formed by ~ 6 hours, and aggregation was approaching completion by ~14 hours (see also Movie 3).…”

The WIPI Gene Family and Neurodegenerative Diseases: Insights From Yeast and Dictyostelium Models

“…Dictyostelium belongs to the amoebozoa group, and although this group of organisms diverged before the opistokonta (fungi and animals), it retains many features of animal cells that have been lost during the evolution of fungi. Cell motility and chemotaxis, phagocytosis and macropynocytosis are very similar to those observed in animal cells and Dictyostelium presents a multicellular stage that allows the study of cell differentiation and morphogenesis (see this series of reviews collected in a special issue dedicated to Dictyostelium in IJDB ( Araki and Saito, 2019 ; Batsios et al, 2019 ; Bloomfield, 2019 ; Bozzaro, 2019 ; Consalvo et al, 2019 ; Escalante and Cardenal-Muñoz, 2019 ; Farinholt et al, 2019 ; Fey et al, 2019 ; Fischer and Eichinger, 2019 ; Ishikawa-Ankerhold and Müller-Taubenberger, 2019 ; Jaiswal et al, 2019 ; Kawabe et al, 2019 ; Kay et al, 2019 ; Knecht et al, 2019 ; Kundert and Shaulsky, 2019 ; Kuspa and Shaulsky, 2019 ; Medina et al, 2019 ; Nanjundiah, 2019 ; Pal et al, 2019 ; Pearce et al, 2019 ; Pergolizzi et al, 2019 ; Schaf et al, 2019 ; Vines and King, 2019 ). Individual Dictyostelium cells ingest bacteria and yeasts in soil and the transition to a multicellular state, triggered when the food source is depleted, is accomplished by aggregation of preexisting cells.…”