Identification of functional modules of AKMT, a novel lysine methyltransferase regulating the motility of Toxoplasma gondii.

The intracellular parasite Toxoplasma gondii is a leading cause of congenital neurological defects. To cause disease, it must reiterate its lytic cycle through host cell invasion, replication, and parasite egress. This requires the parasite to sense changes in its environment and switch between the non-motile (for replication) and motile (for invasion and egress) states appropriately.

A mouse neurodegenerative dynein heavy chain mutation alters dynein motility and localization in Neurospora crassa.

Cytoplasmic dynein is responsible for the transport and delivery of cargoes in organisms ranging from humans to fungi. Dysfunction of dynein motor machinery due to mutations in dynein or its activating complex dynactin can result in one of several neurological diseases in mammals. The mouse Legs at odd angles (Loa) mutation in the tail domain of the dynein heavy chain has been shown to lead to progressive neurodegeneration in mice.

Analyses of dynein heavy chain mutations reveal complex interactions between dynein motor domains and cellular dynein functions.

Cytoplasmic dynein transports cargoes for a variety of crucial cellular functions. However, since dynein is essential in most eukaryotic organisms, the in-depth study of the cellular function of dynein via genetic analysis of dynein mutations has not been practical. Here, we identify and characterize 34 different dynein heavy chain mutations using a genetic screen of the ascomycete fungus Neurospora crassa, in which dynein is nonessential.