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 Water forms 'spine of hydration' around DNA, group finds
26.05.2017 | Cornell University

nachricht How herpesviruses win the footrace against the immune system
26.05.2017 | Helmholtz-Zentrum für Infektionsforschung

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Can the immune system be boosted against Staphylococcus aureus by delivery of messenger RNA?

Staphylococcus aureus is a feared pathogen (MRSA, multi-resistant S. aureus) due to frequent resistances against many antibiotics, especially in hospital infections. Researchers at the Paul-Ehrlich-Institut have identified immunological processes that prevent a successful immune response directed against the pathogenic agent. The delivery of bacterial proteins with RNA adjuvant or messenger RNA (mRNA) into immune cells allows the re-direction of the immune response towards an active defense against S. aureus. This could be of significant importance for the development of an effective vaccine. PLOS Pathogens has published these research results online on 25 May 2017.

Staphylococcus aureus (S. aureus) is a bacterium that colonizes by far more than half of the skin and the mucosa of adults, usually without causing infections....

Im Focus: A quantum walk of photons

Physicists from the University of Würzburg are capable of generating identical looking single light particles at the push of a button. Two new studies now demonstrate the potential this method holds.

The quantum computer has fuelled the imagination of scientists for decades: It is based on fundamentally different phenomena than a conventional computer....

Im Focus: Turmoil in sluggish electrons’ existence

An international team of physicists has monitored the scattering behaviour of electrons in a non-conducting material in real-time. Their insights could be beneficial for radiotherapy.

We can refer to electrons in non-conducting materials as ‘sluggish’. Typically, they remain fixed in a location, deep inside an atomic composite. It is hence...

Im Focus: Wafer-thin Magnetic Materials Developed for Future Quantum Technologies

Two-dimensional magnetic structures are regarded as a promising material for new types of data storage, since the magnetic properties of individual molecular building blocks can be investigated and modified. For the first time, researchers have now produced a wafer-thin ferrimagnet, in which molecules with different magnetic centers arrange themselves on a gold surface to form a checkerboard pattern. Scientists at the Swiss Nanoscience Institute at the University of Basel and the Paul Scherrer Institute published their findings in the journal Nature Communications.

Ferrimagnets are composed of two centers which are magnetized at different strengths and point in opposing directions. Two-dimensional, quasi-flat ferrimagnets...

Im Focus: World's thinnest hologram paves path to new 3-D world

Nano-hologram paves way for integration of 3-D holography into everyday electronics

An Australian-Chinese research team has created the world's thinnest hologram, paving the way towards the integration of 3D holography into everyday...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Marine Conservation: IASS Contributes to UN Ocean Conference in New York on 5-9 June

24.05.2017 | Event News

AWK Aachen Machine Tool Colloquium 2017: Internet of Production for Agile Enterprises

23.05.2017 | Event News

Dortmund MST Conference presents Individualized Healthcare Solutions with micro and nanotechnology

22.05.2017 | Event News

 
Latest News

How herpesviruses win the footrace against the immune system

26.05.2017 | Life Sciences

Water forms 'spine of hydration' around DNA, group finds

26.05.2017 | Life Sciences

First Juno science results supported by University of Leicester's Jupiter 'forecast'

26.05.2017 | Physics and Astronomy

VideoLinks
B2B-VideoLinks
More VideoLinks >>>