Cytoplasmic dynein is a minus-end-directed microtubule motor that participates in multiple cellular activities such as organelle transport and mitotic spindle assembly . To study the dynamic behavior of cytoplasmic dynein in the filamentous fungus Aspergillus nidulans, we replaced the gene for the cytoplasmic dynein heavy chain, nudA, with a gene encoding a green fluorescent protein (GFP)-tagged chimera, GFP-nudA. The GFP-NUDA fusion protein is fully functional in vivo: strains expressing only the GFP-tagged nudA grow as well as wild-type strains. Fluorescence microscopy showed GFP-NUDA to be in comet-like structures that moved in the hyphae toward the growing tip. Retrograde movement of some GFP-NUDA comets after they arrived at the tip was also observed. These dynamics of GFP-NGDA were not observed in cells treated with a microtubule-destabilizing drug, benomyl, suggesting they are microtubule-dependent. The rate of GFP-NGDA tip-ward movement is similar to the rate of cytoplasmic microtubule polymerization toward the hyphal tip, suggesting that GFP-NUDA is associated and moving with the polymerizing ends of microtubules. A mutation in actin-related protein Arp1 of the dynactin complex abolishes the presence of these dynamic GFP-NUDA structures near the hyphal tip, suggesting a targeting role of the dynactin complex.
Xiang, X., Han, G., Winkelmann, D. A., Zuo, W., & Morris, N. R. (2000). Dynamics of cytoplasmic dynein in living cells and the effect of a mutation in the dynactin complex actin-related protein Arp1. Current Biology, 10(10), 603–606. https://doi.org/10.1016/S0960-9822(00)00488-7