Home | Help | Feedback | Subscriptions | Archive | Search | Table of Contents

This Article Full Text (PDF, 892K) PPT slides of all figures Alert me when this article is cited Services Email this article Similar articles in this journal Alert me to new content in the JCB Download to citation manager Citing Articles Citing Articles via CrossRef Citing Articles via Google Scholar Google Scholar Articles by Powell, K. Search for Related Content PubMed Articles by Powell, K. Social Bookmarking                            What's this?

Skating on MTs

Mutant dynactin circles (left) rather than gliding along a microtubule (right). KING/MACMILLAN

Dynactin can skate along the length of a microtubule (MT), giving a boost to the attached dynein motor's forward progress, according to Tara Culver-Hanlon, Stephen King (University of Missouri, Kansas City, MO), and colleagues.

Dynein is a poorly processive motor compared with others like kinesin. "It doesn't stay on the microtubule worth a hoot," says King. To be efficient, dynein needs dynactin, which has its own MT-binding domains. King's group found that dynactin had not only the well-known CAP-Gly MT-binding domain, but also a neighboring basic domain that bound MTs.

When the group attached the domains to beads for single-particle tracking along MTs, the beads moved in distinctly different ways. CAP-Gly beads missing the basic sequence only swiveled around a relatively fixed point on the MT. Beads with only the basic domain or with both domains could swivel too, but they also skated the length of the MT track while still bound to it.

When the dynein motor was added to the mix, the basic domain alone or full-length dynactin increased the motor's processivity. The CAP-Gly domain alone, however, put the brakes on the motor's speed. The basic domain acts like a space-walking astronaut's tether, says King. "When dynein falls off, [the motor] can rebind and keep moving instead of floating off into the cytoplasm."

Reference:

Culver-Hanlon, T.L., et al. 2006. Nat. Cell Biol. doi:10.1038/ncb1370.

Kendall Powell

kendall2{at}nasw.org

CiteULike    Complore    Connotea    Del.icio.us    Digg    Facebook    Reddit    Technorati    Twitter    What's this?

This Article Full Text (PDF, 892K) PPT slides of all figures Alert me when this article is cited Services Email this article Similar articles in this journal Alert me to new content in the JCB Download to citation manager Citing Articles Citing Articles via CrossRef Citing Articles via Google Scholar Google Scholar Articles by Powell, K. Search for Related Content PubMed Articles by Powell, K. Social Bookmarking                            What's this?