Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Making the right contacts to get ahead

07.06.2010
A set of mutant yeast strains allows researchers to identify structural elements that help motor proteins to get moving

Cells are crisscrossed by microtubules, protein cables that provide essential infrastructure and serve as ‘highways’ for moving molecular cargoes. Motor proteins, such as kinesin that travels along microtubules via a multi-step ‘walking’ mechanism, effectively drive this transport.

The broad strokes of this process are well understood generally, but new work from Etsuko Muto and Seiichi Uchimura of the RIKEN Brain Science Institute in Wako in collaboration with physicists at Waseda University, Tokyo, has revealed valuable new details about how microtubule interactions facilitate kinesin movement1.

Kinesin is associated with the nucleotide molecule adenosine diphosphate (ADP) when it first binds microtubules, after which it undergoes a structural change that triggers release of ADP and enables interaction with adenosine triphosphate (ATP). Subsequent enzymatic processing of ATP into ADP triggers additional structural changes, causing kinesin to move forward along the microtubule while also returning the protein to its initial ADP-bound state.

Microtubules are composed of dimers of the protein á- and â-tubulin, but eukaryotic cells can have numerous different tubulin subtypes, making it challenging to investigate molecular-level details of kinesin–tubulin interaction. To overcome this problem, Muto and Uchimura developed yeast strains that express only a single subtype each of á- and â-tubulin, thus enabling simple screening of the effects of individual tubulin mutations. In their most recent work, they have used this approach to extensively characterize points of interaction between kinesin and microtubules by generating 36 yeast strains with individual mutations in either tubulin subunit.

Their data suggest that á-tubulin is primarily responsible in the initial association with kinesin-ADP, with â-tubulin providing important stabilizing interactions following the release of ADP. The researchers were particularly surprised to note that mutations targeting one highly conserved glutamate (E415) in á-tubulin caused a five-fold reduction in kinesin enzymatic activity, apparently by impairing binding-induced release of ADP. “Our results indicate that kinesin binding to residue E415 in á-tubulin transmits a signal to the kinesin nucleotide pocket, triggering its conformational change and leading to release of ADP,” explains Muto. “I did not expect that residues in á-tubulin would play such an important role.”

In future studies, Muto and Uchimura hope to further dissect the amino acid network that communicates these structural changes across the kinesin protein. Since microtubules play a key role in diverse cellular functions beyond molecular transport, Muto believes that their mutational analysis strategy should also offer a powerful tool for studying processes ranging from the separation of chromosome pairs during cell division to cilia-mediated cell propulsion.

The corresponding author for this highlight is based at the Laboratory for Molecular Biophysics, RIKEN Brain Science Institute

Journal information

1. Uchimura, S., Oguchi, Y., Hachikubo, Y., Ishiwata, S. & Muto, E. Key residues on microtubule responsible for activation of kinesin ATPase. The EMBO Journal 29, 1167–1175 (2010)

gro-pr | Research asia research news
Further information:
http://www.rikenresearch.riken.jp/eng/research/6281
http://www.researchsea.com

Further reports about: ADP ATP RIKEN Science TV Uchimura cellular function structural changes

More articles from Life Sciences:

nachricht Researchers target protein that protects bacteria's DNA 'recipes'
21.08.2018 | University of Rochester

nachricht Protein interaction helps Yersinia cause disease
21.08.2018 | Schwedischer Forschungsrat - The Swedish Research Council

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: It’s All in the Mix: Jülich Researchers are Developing Fast-Charging Solid-State Batteries

There are currently great hopes for solid-state batteries. They contain no liquid parts that could leak or catch fire. For this reason, they do not require cooling and are considered to be much safer, more reliable, and longer lasting than traditional lithium-ion batteries. Jülich scientists have now introduced a new concept that allows currents up to ten times greater during charging and discharging than previously described in the literature. The improvement was achieved by a “clever” choice of materials with a focus on consistently good compatibility. All components were made from phosphate compounds, which are well matched both chemically and mechanically.

The low current is considered one of the biggest hurdles in the development of solid-state batteries. It is the reason why the batteries take a relatively long...

Im Focus: Color effects from transparent 3D-printed nanostructures

New design tool automatically creates nanostructure 3D-print templates for user-given colors
Scientists present work at prestigious SIGGRAPH conference

Most of the objects we see are colored by pigments, but using pigments has disadvantages: such colors can fade, industrial pigments are often toxic, and...

Im Focus: Unraveling the nature of 'whistlers' from space in the lab

A new study sheds light on how ultralow frequency radio waves and plasmas interact

Scientists at the University of California, Los Angeles present new research on a curious cosmic phenomenon known as "whistlers" -- very low frequency packets...

Im Focus: New interactive machine learning tool makes car designs more aerodynamic

Scientists develop first tool to use machine learning methods to compute flow around interactively designable 3D objects. Tool will be presented at this year’s prestigious SIGGRAPH conference.

When engineers or designers want to test the aerodynamic properties of the newly designed shape of a car, airplane, or other object, they would normally model...

Im Focus: Robots as 'pump attendants': TU Graz develops robot-controlled rapid charging system for e-vehicles

Researchers from TU Graz and their industry partners have unveiled a world first: the prototype of a robot-controlled, high-speed combined charging system (CCS) for electric vehicles that enables series charging of cars in various parking positions.

Global demand for electric vehicles is forecast to rise sharply: by 2025, the number of new vehicle registrations is expected to reach 25 million per year....

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

LaserForum 2018 deals with 3D production of components

17.08.2018 | Event News

Within reach of the Universe

08.08.2018 | Event News

A journey through the history of microscopy – new exhibition opens at the MDC

27.07.2018 | Event News

 
Latest News

Air pollution leads to cardiovascular diseases

21.08.2018 | Ecology, The Environment and Conservation

Researchers target protein that protects bacteria's DNA 'recipes'

21.08.2018 | Life Sciences

A paper battery powered by bacteria

21.08.2018 | Power and Electrical Engineering

VideoLinks
Science & Research
Overview of more VideoLinks >>>