Newly discovered rings around microtubules, assembled from the Dam1 protein complex, may provide the dynamic linkage at microtubule ends for force generation coupled to microtubule depolymerization and polymerization.

Microtubules are rigid, proteinaceous filaments required to organize and rearrange the interior of cells. They organize space by two mechanisms, including acting as the tracks for long-distance cargo transporters, such as kinesin-1, and by forming a network that supports the shape of the cell. The microtubule network is composed of microtubules and a bevy of associated proteins and enzymes that...

Microtubule depolymerization can provide force to transport different protein complexes and protein-coated beads in vitro. The underlying mechanisms are thought to play a vital role in the microtubule-dependent chromosome motions during cell division, but the relevant proteins and their exact roles are ill-defined. Thus, there is a growing need to develop assays with which to study such motilit...

Spermatogenesis involves coordinated processes, including meiosis, to produce functional gametes. We previously reported Topaz1 as a germ cell-specific gene highly conserved in vertebrates. knockout males are sterile with testes that lack haploid cells because of meiotic arrest after prophase I. To better characterize –/– testes, we used RNA-sequencing analyses at two different developmental st...

Microtubule depolymerization dynamics in the spindle are regulated by kinesin-13, a nonprocessive kinesin motor protein that depolymerizes microtubules at the plus and minus ends. Here we show that a single kinesin-13 homolog regulates flagellar length dynamics, as well as other interphase and mitotic dynamics in Giardia intestinalis, a widespread parasitic diplomonad protist. Both green fluore...

Chromosome segregation during mitosis and meiosis relies on the spindle and the functions of numerous microtubule-associated proteins (MAPs). One of the best-studied spindle MAPs is the highly conserved TPX2, which has been reported to have characteristic intracellular dynamics and molecular activities, such as nuclear localisation in interphase, poleward movement in the metaphase spindle, micr...

The novel concept of a centrosomal anchoring complex, which is distinct from the gamma-tubulin nucleating complex, has previously been proposed following studies on cochlear epithelial cells. In this investigation we present evidence from two different cell systems which suggests that the centrosomal protein ninein is a strong candidate for the proposed anchoring complex. Ninein has recently be...

Centrosomes are considered to be the major sites of microtubule nucleation in mitotic cells (reviewed in ), yet mitotic spindles can still form after laser ablation or disruption of centrosome function . Although kinetochores have been shown to nucleate microtubules, mechanisms for acentrosomal spindle formation remain unclear. Here, we performed live-cell microscopy of GFP-tubulin to examine s...

Highly conserved EB1 family proteins bind to the growing ends of microtubules, recruit multiple cargo proteins, and are critical for making dynamic microtubules in vivo. However, it is unclear how these master regulators of microtubule plus ends promote microtubule dynamics. In this paper, we identify a novel EB1 cargo protein, Sentin. Sentin depletion in Drosophila melanogaster S2 cells, simil...