The LIS1-related protein NUDF of Aspergillus nidulans and its interaction partner NUDE bind directly to specific subunits of dynein and dynactin and to alpha- and gamma-tubulin

The NUDF protein of Aspergillus nidulans, which is required for nuclear mig ration through the fungal mycelium, closely resembles the LIST protein requ ired for migration of neurons to the cerebral cortex in humans. Genetic exp eriments suggested that NUDF influences nuclear migration by affecting cyto plasmic dynein. NUDF interacts with another protein, NUDE, which also affec ts nuclear migration in A. nidulans. Interactions among LIST, NUDE, dynein, and gamma -tubulin have been demonstrated in animal cells. In this paper w e examine the interactions of the A. nidulans NUDE and NUDE proteins with c omponents of dynein, dynactin, and with alpha- and gamma -tubulin. We show that NUDF binds directly to alpha- and gamma -tubulin and to the first P-lo op of the cytoplasmic dynein heavy chain, whereas NUDE binds directly to a- and y-tubulin, to NUDK (actin-related protein 1), and to the NUDG dynein L C8 light chain. The data suggest a direct role for NUDF in regulation of th e dynein heavy chain and an effect on other dynein/dynactin subunits via NU DE. The interactions between NUDE, NUDF, and y-tubulin suggest that this pr otein may also be involved in the regulation of dynein function. Additive i nteractions between NUDE and dynein and dynactin subunits suggest that NUDE acts as a scaffolding factor between components.