Correct spindle position is an essential feature of cell division from yeast to man. In animal cells, the cleavage furrow is specified so as to bisect the mitotic spindle. Therefore, correct orientation of the spindle along a given axis, as well as its accurate placement on this axis (hereafter collectively referred to as “spindle positioning” for simplicity), is critical for dictating the rela...

Post-translational modifications of tubulin, such as the removal of the C-terminal tyrosine of a-tubulin, have long been proposed to influence the ability of microtubule motors to walk along the microtubule surface. This hypothesis has now been tested for cytoplasmic dynein-1 (dynein), revealing that active dynein–dynactin– adaptor complexes prefer to start moving on tyrosinated microtubules. T...

Dynein motors move various cargos along microtubules within the cytoplasm and power the beating of cilia and flagella. An unusual feature of dynein is that its microtubule-binding domain (MTBD) is separated from its ring-shaped AAA+ adenosine triphosphatase (ATPase) domain by a 15-nanometer coiled-coil stalk. We report the crystal structure of the mouse cytoplasmic dynein MTBD and a portion of ...

Experimental observations on cyclic splitting and bending by a flagellar doublet pair are modeled using forces obtained from a model for dynein mechanochemistry, based on ideas introduced by Andrew Huxley and Terrill Hill and extended previously for modeling flagellar movements. The new feature is elastic attachment of dynein to the A doublet, which allows movement perpendicular to the A double...

We investigated potential roles of cytoplasmic dynein in organizing axonal microtubules either by depleting dynein heavy chain from cultured neurons or by experimentally disrupting dynactin. The former was accomplished by siRNA while the latter was accomplished by overexpressing P50-dynamitin. Both methods resulted in a persistent reduction in the frequency of transport of short microtubules. T...

Glycogen synthase kinase 3 (GSK-3) has been linked to regulation of kinesin-dependent axonal transport in squid and flies, and to indirect regulation of cytoplasmic dynein. We have now found evidence for direct regulation of dynein by mammalian GSK-3β in both neurons and non-neuronal cells. GSK-3β coprecipitates with and phosphorylates mammalian dynein. Phosphorylation of dynein intermediate ch...

Cytoplasmic dynein intermediate chain (IC) mediates dynein-dynactin interaction in vitro (Karki, S., and E.L. Holzbaur. 1995. J. Biol. Chem. 270:28806-28811; Vaughan, K.T., and R.B. Vallee. 1995. J. Cell Biol. 131:1507-1516). To investigate the physiological role of IC and dynein-dynactin interaction, we expressed IC truncations in wild-type Dictyostelium cells. ICDeltaC associated with dynacti...

The 19S outer arm dynein of trout sperm flagella is a complex of proteins composed of two heavy chains, five intermediate chains and at least six light chains. After dialysis against a low ionic strength buffer, its beta subunit was purified and used to generate a rabbit polyclonal antibody. This polyclonal antibody reacted strongly with the trout beta dynein heavy chain (DHC) but not with the ...

The centrosome is generally maintained at the center of the cell. In animal cells, centrosome centration is powered by the pulling force of microtubules, which is dependent on cytoplasmic dynein. However, it is unclear how dynein brings the centrosome to the cell center, i.e., which structure inside the cell functions as a substrate to anchor dynein. Here, we provide evidence that a population ...

Axonemal dyneins are force-generating ATPases that produce ciliary and flagellar movement. A dynein has large heavy chain(s) in which there are multiple (4-6) ATP-binding consensus sequences (P-loops) as well as intermediate and light chains, constituting a very large complex. We purified a monomeric form of dynein (dynein-a) that has at least three light chains from 14S dyneins of Tetrahymena ...