A potential LINC complex

Wagner, Mirjam (2023): A potential LINC complex: the SUN-like protein TgSLP1 plays an essential role in cell division in the apicomplexan parasite Toxoplasma gondii. Dissertation, LMU München: Faculty of Veterinary Medicine

Abstract

Apicomplexan parasites include some of the most important pathogens, such as Plasmodium spp., the causative agent of malaria, or Toxoplasma gondii, the causative agent of toxoplasmosis. As obligate intracellular parasites, Apicomplexa invade host cells in an active process, where they replicate within a parasitophorous vacuole, followed by egress and lysis of the host cell. T. gondii parasites use a unique mode of cell division called endodyogeny, in which two daughter cells form within the mother parasite. Connections between the nucleus and the cytoskeleton are important for positioning and division of the nucleus. In most eukaryotes, the LINC complex (Linker of Nucleoskeleton and Cytoskeleton) spans the outer and inner nuclear membranes and connects the nucleus to the cytoskeleton. In opisthokonts, it is composed of KASH domain proteins and SUN domain proteins. Given that the nucleus is positioned at the posterior pole of T. gondii, it can be speculated that apicomplexan parasites must have a similar mechanism that integrates the nucleus and the cytoskeleton. Here, three UNC family proteins were identified in the genome of the apicomplexan parasite T.gondii. While the UNC-50 protein TgUNC1 localised to the Golgi and appeared to be not essential for the parasite, the SUN domain protein TgSLP2 showed a diffuse pattern throughout the parasite. The second SUN domain protein, TgSLP1, was expressed in a cell-cycle dependent manner, localised close to the mitotic spindle and conditional knockout of TgSLP1 leads to failure of nuclear division and loss of centrocone integrity.

• Item Type: Theses (Dissertation, LMU Munich)
• Keywords: Replication, SUN protein, LINC, parasite, Toxoplasma gondii
• Subjects: 500 Natural sciences and mathematics; 500 Natural sciences and mathematics > 590 Zoological sciences
• Faculties: Faculty of Veterinary Medicine
• Language: English
• Date of oral examination: 22. July 2023
• 1. Referee: Meissner, Markus
• Signature of the printed copy: 0001/UMC 29898