Differential requirements for cyclase-associated protein (CAP) in actin-dependent processes of Toxoplasma gondii

• Published in: eLife Vol. 8
• Main Authors: Hunt, Alex, Russell, Matthew Robert Geoffrey, Wagener, Jeanette, Kent, Robyn, Carmeille, Romain, Peddie, Christopher J, Collinson, Lucy, Heaslip, Aoife, Ward, Gary E, Treeck, Moritz
• Format: Journal Article
• Language: English
• Published: England eLife Science Publications, Ltd 02.10.2019; eLife Sciences Publications Ltd; eLife Sciences Publications, Ltd
• Subjects: Actin; Actins - metabolism; Antigens; Bacterial proteins; Binding proteins; cell biology; Cell Communication; Cell Division; Cell interactions; Cell signaling; Clonal deletion; Crick, Francis; cyclase-associated protein; Cysts; Electron microscopy; Gene Deletion; Isoforms; Laboratories; Microbiology and Infectious Disease; Microscopy; Motility; Muscle proteins; Parasites; parasitology; Physiological aspects; Protein binding; Protein Isoforms - deficiency; Protein Isoforms - metabolism; Proteins; Protozoan Proteins - genetics; Protozoan Proteins - metabolism; Toxoplasma; Toxoplasma - metabolism; Toxoplasma gondii; United Kingdom; United Kingdom > UK; United States > US; actin; Toxoplasma gondii; cell biology; cyclase-associated protein; infectious disease; microbiology; parasitology
• ISSN: 2050-084X; 2050-084X
• DOI: 10.7554/eLife.50598

Toxoplasma gondii contains a limited subset of actin binding proteins. Here we show that the putative actin regulator cyclase-associated protein (CAP) is present in two different isoforms and its deletion leads to significant defects in some but not all actin dependent processes. We observe defects in cell-cell communication, daughter cell orientation and the juxtanuclear accumulation of actin, but only modest defects in synchronicity of division and no defect in the replication of the apicoplast. 3D electron microscopy reveals that loss of CAP results in a defect in formation of a normal central residual body, but parasites remain connected within the vacuole. This dissociates synchronicity of division and parasite rosetting and reveals that establishment and maintenance of the residual body may be more complex than previously thought. These results highlight the different spatial requirements for F-actin regulation in Toxoplasma which appear to be achieved by partially overlapping functions of actin regulators.