Activation of cytoplasmic dynein motility by dynactin-cargo adapter complexes

See allHide authors and affiliations

Science  18 Jul 2014:
Vol. 345, Issue 6194, pp. 337-341
DOI: 10.1126/science.1254198

You are currently viewing the abstract.

View Full Text

Log in to view the full text

Log in through your institution

Log in through your institution

How dynein makes the right moves

The molecular motor cytoplasmic dynein moves a wide range of different intracellular cargoes. Dynein's activity in vivo requires another protein, dynactin, but exactly why that should be has been very unclear. Although in vitro experiments have provided some evidence that dynactin increases dynein's processivity, the resulting dynein motility has never come close to matching dynein's cargo-transporting activity in living cells. Now, McKenney et al. show that tripartite complexes of dynein, dynactin, and an adaptor molecule are highly processive in vitro, moving the sort of distances that dynein transports cargo in vivo (see the Perspective by Allan).

Science, this issue p. 337; see also p. 271


Cytoplasmic dynein is a molecular motor that transports a large variety of cargoes (e.g., organelles, messenger RNAs, and viruses) along microtubules over long intracellular distances. The dynactin protein complex is important for dynein activity in vivo, but its precise role has been unclear. Here, we found that purified mammalian dynein did not move processively on microtubules in vitro. However, when dynein formed a complex with dynactin and one of four different cargo-specific adapter proteins, the motor became ultraprocessive, moving for distances similar to those of native cargoes in living cells. Thus, we propose that dynein is largely inactive in the cytoplasm and that a variety of adapter proteins activate processive motility by linking dynactin to dynein only when the motor is bound to its proper cargo.

View Full Text

Stay Connected to Science