2025/11/21 by Vikash Verma, Patricia Wadsworth, Thomas J. Maresca · 1 voice
Biochemistry, Genetics and Molecular Biology · Neuroscience · #Microtubule and mitosis dynamics #Photoreceptor and optogenetics research #Protist diversity and phylogeny
paper · doi:10.7554/elife.94963.2
openalex publication_date 2025/11/21 · openalex created_date 2025/11/23 · openalex updated_date 2026/07/14
Minus-end directed transport along microtubules in eukaryotes is primarily mediated by cytoplasmic dynein and its cofactor dynactin. Significant advances have been made in recent years characterizing human dynein-dynactin structure and function using in vitro assays, however, there is limited knowledge about the motile properties and functional organization of dynein-dynactin in living human cells. Total internal reflection fluorescence microscopy (TIRFM) of CRISPR-engineered human cells is employed here to visualize fluorescently tagged dynein heavy chain (DHC) and p50 with high spatio-temporal resolution. We find that p50 and DHC exhibit indistinguishable motility properties in their velocities, run lengths, and run times. The dynein-dynactin complexes are fast (∼1.2 μm/s) and run for several microns (∼2.7 μm). Quantification of the fluorescence intensities of motile puncta reveals that dynein-dynactin runs are mediated by at least one DHC dimer while the velocity is consistent with that measured for double dynein (two DHC dimers) complexes in vitro.