Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Plant gene related to cancer treatment may foster new oncology drugs

23.11.2005


Two proteins involved in the process that controls plant growth may help explain why human cells reject chemotherapy drugs, according to an international team of scientists.



Researchers from Purdue University and Kyoto University in Japan have shown for the first time that proteins similar to multi-drug resistant proteins in humans move a plant growth hormone into cells, said Purdue plant cell biologist Angus Murphy. Because plant proteins called P-glycoproteins (PGPs) are closely related to human P-glycoproteins that impact chemotherapy effectiveness, discovery of methods to control the plant protein’s activity may aid in development of therapies to reduce drug dosages administered to cancer patients, Murphy said.

Murphy is corresponding author of the study published in the November issue of Plant Cell. He also is corresponding author of a related article published in October’s Plant Journal.


"Results of this research will give us a better idea of the functioning of the multi-drug resistance process in which human cancer cells reject anticancer treatments," Murphy said.

Results of the two studies suggest a previously unknown relationship between two protein families involved in this process, he said. Working together, the proteins apparently move molecules of the plant growth hormone auxin through cell walls. In humans, related proteins rid cells of toxins such as cancer drugs.

"The findings of these two studies have important implications for biomedicine because we now can identify the parts of these proteins that determine whether cells take up or throw off different molecules, such as cancer drugs," Murphy said.

In the Plant Journal study, Murphy and his collaborators at the University of Zurich showed for first time that PGP1, a P-glycoprotein from the commonly used experimental plant Arabidopsis, directly transports auxin out of plant cells and also out of yeast and mammalian cells. In the Plant Cell study, they found that other PGP proteins move auxin into cells.

"Auxin molecules essentially are pulled through the cell membrane by PGP transport proteins," Murphy said. "It’s an energetic process that happens like pulling a rope through something sticky."

Both the multi-drug resistant PGPs in people and plants are part of a large family of proteins, called ATP-binding cassette (ABC) proteins, that act as delivery trucks to detoxify cells, send messages from cell to cell to influence biochemical reactions, and to regulate those reactions. The ABC proteins are so named because they must bind with ATP, the main cell energy source, in order to fulfill their mission.

The best known member of another class of transport proteins, PIN1, also may be a transporter, but appears to function primarily as an aide rather than the delivery truck for auxin transport, Murphy said. This finding revealed that PINs and PGPs may function together in long-distance auxin transport, according to the Plant Journal article. Named for the pin-shaped appearance of the mutant originally used to identify the gene that directs the activities of PIN1, these proteins are members of the major protein family, called facilators, that aid processes such as hormone transport.

Recent evidence suggests that teamwork between PGP and PIN proteins determines the direction auxin moves and, therefore, how the plant develops, Murphy said. In plants, shape, height and bending in response to light and gravity are largely determined by the direction and amount of auxin moving through their tissues.

Murphy and his collaborators on the Plant Journal study found that PGP1 and PGP19 move the hormone out of cells.

In the November Plant Cell report, Murphy’s research team reported that another P-glycoprotein, PGP4, functions in the opposite direction, providing the boost needed to import the hormone auxin into cells and to increase the amount transported.

"With these two studies, we’ve shown for the first time that both the uptake and release of molecules are mediated by interaction between the PGP transporter proteins and PIN facilitator proteins," Murphy said.

Other researchers involved with the Plant Cell study were Joshua Blakeslee, Wendy Peer, Boosaree Titapiwatanakun, Anindita Bandyopadhyay, Srinivas Makam, Ok Ran Lee and Elizabeth Richards, all of the Purdue Department of Botany and Plant Pathology; Kazuyoshi Teraska and Fumihiko Sato of the Laboratory of Molecular & Cellular Biology of Totipotency, Kyoto University, Japan; and Kazufumi Yazaki of the Laboratory of Plant Gene Expression, Kyoto University. Teraska, Blakeslee and Titapiwatanakun each contributed equally to the research project and as authors of the journal paper.

The U.S. National Science Foundation; the Ministry of Education, Culture, Sports, Science and Technology of Japan; and the Uehara Foundation of Kentucky provided support for this research.

On the Plant Journal paper, Markus Geisler of the Basel-Zurich Plant Science Center, University of Zurich, and Blakeslee were co-lead authors and contributed equally to the research; Murphy was corresponding author; and Enrico Martinola, of the University of Zurich, was senior author. The U.S. National Science Foundation and the Swiss National Science Foundation provided funding for the study.

Writer: Susan A. Steeves, (765) 496-7481, ssteeves@purdue.edu

Source: Angus Murphy, (765) 496-7956, murphy@purdue.edu

Ag Communications: (765) 494-2722; Beth Forbes, forbes@purdue.edu, Agriculture News Page

Susan A. Steeves | EurekAlert!
Further information:
http://www.purdue.edu

More articles from Life Sciences:

nachricht Toward a 'smart' patch that automatically delivers insulin when needed
18.01.2017 | American Chemical Society

nachricht 127 at one blow...
18.01.2017 | Stiftung Zoologisches Forschungsmuseum Alexander Koenig, Leibniz-Institut für Biodiversität der Tiere

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: How gut bacteria can make us ill

HZI researchers decipher infection mechanisms of Yersinia and immune responses of the host

Yersiniae cause severe intestinal infections. Studies using Yersinia pseudotuberculosis as a model organism aim to elucidate the infection mechanisms of these...

Im Focus: Interfacial Superconductivity: Magnetic and superconducting order revealed simultaneously

Researchers from the University of Hamburg in Germany, in collaboration with colleagues from the University of Aarhus in Denmark, have synthesized a new superconducting material by growing a few layers of an antiferromagnetic transition-metal chalcogenide on a bismuth-based topological insulator, both being non-superconducting materials.

While superconductivity and magnetism are generally believed to be mutually exclusive, surprisingly, in this new material, superconducting correlations...

Im Focus: Studying fundamental particles in materials

Laser-driving of semimetals allows creating novel quasiparticle states within condensed matter systems and switching between different states on ultrafast time scales

Studying properties of fundamental particles in condensed matter systems is a promising approach to quantum field theory. Quasiparticles offer the opportunity...

Im Focus: Designing Architecture with Solar Building Envelopes

Among the general public, solar thermal energy is currently associated with dark blue, rectangular collectors on building roofs. Technologies are needed for aesthetically high quality architecture which offer the architect more room for manoeuvre when it comes to low- and plus-energy buildings. With the “ArKol” project, researchers at Fraunhofer ISE together with partners are currently developing two façade collectors for solar thermal energy generation, which permit a high degree of design flexibility: a strip collector for opaque façade sections and a solar thermal blind for transparent sections. The current state of the two developments will be presented at the BAU 2017 trade fair.

As part of the “ArKol – development of architecturally highly integrated façade collectors with heat pipes” project, Fraunhofer ISE together with its partners...

Im Focus: How to inflate a hardened concrete shell with a weight of 80 t

At TU Wien, an alternative for resource intensive formwork for the construction of concrete domes was developed. It is now used in a test dome for the Austrian Federal Railways Infrastructure (ÖBB Infrastruktur).

Concrete shells are efficient structures, but not very resource efficient. The formwork for the construction of concrete domes alone requires a high amount of...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

12V, 48V, high-voltage – trends in E/E automotive architecture

10.01.2017 | Event News

2nd Conference on Non-Textual Information on 10 and 11 May 2017 in Hannover

09.01.2017 | Event News

Nothing will happen without batteries making it happen!

05.01.2017 | Event News

 
Latest News

A big nano boost for solar cells

18.01.2017 | Power and Electrical Engineering

Glass's off-kilter harmonies

18.01.2017 | Materials Sciences

Toward a 'smart' patch that automatically delivers insulin when needed

18.01.2017 | Life Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>