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 Scientists uncover the role of a protein in production & survival of myelin-forming cells
19.07.2018 | Advanced Science Research Center, GC/CUNY

nachricht NYSCF researchers develop novel bioengineering technique for personalized bone grafts
18.07.2018 | New York Stem Cell Foundation

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Future electronic components to be printed like newspapers

A new manufacturing technique uses a process similar to newspaper printing to form smoother and more flexible metals for making ultrafast electronic devices.

The low-cost process, developed by Purdue University researchers, combines tools already used in industry for manufacturing metals on a large scale, but uses...

Im Focus: First evidence on the source of extragalactic particles

For the first time ever, scientists have determined the cosmic origin of highest-energy neutrinos. A research group led by IceCube scientist Elisa Resconi, spokesperson of the Collaborative Research Center SFB1258 at the Technical University of Munich (TUM), provides an important piece of evidence that the particles detected by the IceCube neutrino telescope at the South Pole originate from a galaxy four billion light-years away from Earth.

To rule out other origins with certainty, the team led by neutrino physicist Elisa Resconi from the Technical University of Munich and multi-wavelength...

Im Focus: Magnetic vortices: Two independent magnetic skyrmion phases discovered in a single material

For the first time a team of researchers have discovered two different phases of magnetic skyrmions in a single material. Physicists of the Technical Universities of Munich and Dresden and the University of Cologne can now better study and understand the properties of these magnetic structures, which are important for both basic research and applications.

Whirlpools are an everyday experience in a bath tub: When the water is drained a circular vortex is formed. Typically, such whirls are rather stable. Similar...

Im Focus: Breaking the bond: To take part or not?

Physicists working with Roland Wester at the University of Innsbruck have investigated if and how chemical reactions can be influenced by targeted vibrational excitation of the reactants. They were able to demonstrate that excitation with a laser beam does not affect the efficiency of a chemical exchange reaction and that the excited molecular group acts only as a spectator in the reaction.

A frequently used reaction in organic chemistry is nucleophilic substitution. It plays, for example, an important role in in the synthesis of new chemical...

Im Focus: New 2D Spectroscopy Methods

Optical spectroscopy allows investigating the energy structure and dynamic properties of complex quantum systems. Researchers from the University of Würzburg present two new approaches of coherent two-dimensional spectroscopy.

"Put an excitation into the system and observe how it evolves." According to physicist Professor Tobias Brixner, this is the credo of optical spectroscopy....

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

Leading experts in Diabetes, Metabolism and Biomedical Engineering discuss Precision Medicine

13.07.2018 | Event News

Conference on Laser Polishing – LaP: Fine Tuning for Surfaces

12.07.2018 | Event News

11th European Wood-based Panel Symposium 2018: Meeting point for the wood-based materials industry

03.07.2018 | Event News

 
Latest News

A smart safe rechargeable zinc ion battery based on sol-gel transition electrolytes

20.07.2018 | Power and Electrical Engineering

Reversing cause and effect is no trouble for quantum computers

20.07.2018 | Information Technology

Princeton-UPenn research team finds physics treasure hidden in a wallpaper pattern

20.07.2018 | Materials Sciences

VideoLinks
Science & Research
Overview of more VideoLinks >>>