Characterization of the Novel Mitochondrial Genome Segregation Factor TAP110 in Trypanosoma brucei

ABSTRACT: Mitochondrial genome inheritance has been extensively studied in only a handful of model organisms, all belonging to the Opisthokonta eukaryotic supergroup. To understand mitochondrial evolution in more detail, it is important to include organisms of other supergroups such as Excavata (e.g. T. brucei) in our studies. To assure correct inheritance of the replicated kDNA to the two daughter cells in T. brucei , it is anchored to the flagellum that drives kDNA segregation during cell division. The structure connecting the kDNA to the basal body has been described as the tripartite attachment complex (TAC). Several components of that TAC structure and how they assemble has been described in the last few years. It remains elusive how the TAC, inside the mitochondrion, can connect to the kDNA. Here, we present data on the TAC associated protein 110 (TAP110). TAP110 is a 110 kDa protein that shows sequence similarities to a histone linker protein. With super-resolution microscopy, we show that TAP110 co-localizes with TAC102, a TAC component of the unilateral filaments in the mitochondrion. In contrast to other kDNA segregation factors characterized previously, TAP110 remains only partially associated with the flagellum after DNaseI and detergent treatment. Overexpression of TAP110 leads to a delay in the separation of the replicated kDNA networks and thus an increase in cells with replicated but non-segregated kDNA. The depletion of TAC102 leads to loss of TAP110, suggesting that TAP110 is more proximal to the kDNA than TAC102. Furthermore, we demonstrate that the TAC, but not the kDNA, is required for correct TAP110 localization. Blue native suggests that TAP110 might interact with other proteins to form a >669 kDa complex. Interestingly, TAP110 can only be solubilized in dyskinetoplastic cells suggesting a direct interaction with the kDNA.

INSTRUMENT(S): Orbitrap Exploris 480

ORGANISM(S): Trypanosoma Brucei

SUBMITTER: F Butter  

LAB HEAD: Falk Butter

PROVIDER: PXD019665 | Pride | 2021-03-02

REPOSITORIES: Pride