Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Building new connections

20.04.2009
Two newly discovered proteins may offer a breakthrough in understanding the function of an enigmatic network of protein fibers

Cells are crisscrossed by microtubules, protein cables that provide infrastructure, which facilitate cellular migration and assist in transport of molecular cargo, among other functions.

Most microtubules radiate out from structures known as centrosomes, but many cells also contain non-centrosomal microtubules of ambiguous function that are anchored to yet-unknown cellular targets.

For example, in epithelia—cell sheets that compose tissues including the skin and digestive tract—evidence has suggested that microtubules may interact with adherens junctions (AJs), protein complexes that connect epithelial cells together. “However, it was not clearly understood whether and how microtubules were involved in AJ formation,” says Masatoshi Takeichi, of the RIKEN Center for Developmental Biology in Kobe.

Fortunately, a new study by Takeichi’s team, including lead author Wenxiang Meng, offers some illumination. The researchers were looking for interacting partners for p120-catenin, a protein that participates in formation of the zonula adherens (ZA)—bands of AJs that encircle epithelial cells, reinforcing their shape and linking them tightly into two-dimensional sheets.

Their search led to the identification of PLEKHA7 and Nezha, two novel proteins that appear to provide the ‘missing link’ between the ZA and the microtubule network1. Nezha binds to PLEKHA7, which interacts directly with p120, and both Nezha and PLEKHA7 localize to the ZA, where they appear to play an important role in maintaining its integrity.

Meng and Takeichi subsequently found that Nezha interacts directly with non-centrosomal microtubules. Every microtubule has a defined ‘minus’ and ‘plus’ end, with fiber growth occurring exclusively taking place at the latter. Nezha binds specifically to microtubule minus ends, enabling further extension at the plus end, and this association seems to play an essential part in enabling PLEKHA7-Nezha stabilization of the ZA.

Although the details of microtubule involvement in the ZA are still unclear, the researchers uncovered a promising lead when they identified a motor protein, KIFC3, which travels along microtubules towards PLEKHA7-Nezha-associated junctions. “Minus-end directed motors like KIFC3 may utilize these microtubules as a ‘rail’ to transport cargo necessary to maintain the ZA,” says Takeichi.

These findings raise many new questions, but also represent major progress in cell biology, confirming the involvement of microtubules in maintenance of cell-cell junctions and revealing factors that help mediate this function. “To my knowledge, Nezha is the first non-centrosomal protein shown to tether the microtubule minus-ends,” says Takeichi. “These findings are thus a breakthrough for our deeper understanding of the dynamics and biological roles of non-centrosomal microtubules.”

Reference

1. Meng, W., Mushika, Y., Ichii, T. & Takeichi, M. Anchorage of microtubule minus ends to adherens junctions regulates epithelial cell-cell contacts. Cell 135, 948–959 (2008).

The corresponding author for this highlight is based at the RIKEN Laboratory for Cell Adhesion and Tissue Patterning

Saeko Okada | Research asia research news
Further information:
http://www.rikenresearch.riken.jp/research/687/
http://www.researchsea.com

More articles from Life Sciences:

nachricht New risk factors for anxiety disorders
24.02.2017 | Julius-Maximilians-Universität Würzburg

nachricht Stingless bees have their nests protected by soldiers
24.02.2017 | Johannes Gutenberg-Universität Mainz

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Breakthrough with a chain of gold atoms

In the field of nanoscience, an international team of physicists with participants from Konstanz has achieved a breakthrough in understanding heat transport

In the field of nanoscience, an international team of physicists with participants from Konstanz has achieved a breakthrough in understanding heat transport

Im Focus: DNA repair: a new letter in the cell alphabet

Results reveal how discoveries may be hidden in scientific “blind spots”

Cells need to repair damaged DNA in our genes to prevent the development of cancer and other diseases. Our cells therefore activate and send “repair-proteins”...

Im Focus: Dresdner scientists print tomorrow’s world

The Fraunhofer IWS Dresden and Technische Universität Dresden inaugurated their jointly operated Center for Additive Manufacturing Dresden (AMCD) with a festive ceremony on February 7, 2017. Scientists from various disciplines perform research on materials, additive manufacturing processes and innovative technologies, which build up components in a layer by layer process. This technology opens up new horizons for component design and combinations of functions. For example during fabrication, electrical conductors and sensors are already able to be additively manufactured into components. They provide information about stress conditions of a product during operation.

The 3D-printing technology, or additive manufacturing as it is often called, has long made the step out of scientific research laboratories into industrial...

Im Focus: Mimicking nature's cellular architectures via 3-D printing

Research offers new level of control over the structure of 3-D printed materials

Nature does amazing things with limited design materials. Grass, for example, can support its own weight, resist strong wind loads, and recover after being...

Im Focus: Three Magnetic States for Each Hole

Nanometer-scale magnetic perforated grids could create new possibilities for computing. Together with international colleagues, scientists from the Helmholtz Zentrum Dresden-Rossendorf (HZDR) have shown how a cobalt grid can be reliably programmed at room temperature. In addition they discovered that for every hole ("antidot") three magnetic states can be configured. The results have been published in the journal "Scientific Reports".

Physicist Dr. Rantej Bali from the HZDR, together with scientists from Singapore and Australia, designed a special grid structure in a thin layer of cobalt in...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Booth and panel discussion – The Lindau Nobel Laureate Meetings at the AAAS 2017 Annual Meeting

13.02.2017 | Event News

Complex Loading versus Hidden Reserves

10.02.2017 | Event News

International Conference on Crystal Growth in Freiburg

09.02.2017 | Event News

 
Latest News

Stingless bees have their nests protected by soldiers

24.02.2017 | Life Sciences

New risk factors for anxiety disorders

24.02.2017 | Life Sciences

MWC 2017: 5G Capital Berlin

24.02.2017 | Trade Fair News

VideoLinks
B2B-VideoLinks
More VideoLinks >>>