Featured Research

from universities, journals, and other organizations

When a gene is worth two: Same gene fulfills different biological roles in plants

Date:
March 22, 2013
Source:
Instituto Gulbenkian de Ciência (IGC)
Summary:
The notion that each gene can only codify for a single protein has been challenged for some years. Yet, the functional outcomes that may result from genes encoding more than one protein are still largely unknown. Now, botanists have discovered a gene -- ZIFL1 -- that produces two different proteins with completely distinct locations and functions in the plant.

Expression of the ZIFL1 gene in the root (green fluorescence, left panel) and in the stomata of leaves (blue staining, right panel).
Credit: Estelle Remy, IGC

The notion that each gene can only codify for a single protein has been challenged for some years. Yet, the functional outcomes that may result from genes encoding more than one protein are still largely unknown. Now, in a study published in the latest issue of The Plant Cell journal, a group of scientists led by Paula Duque at the Instituto Gulbenkian de Ciência (IGC, Portugal) discovered a gene -- ZIFL1 -- that has the particularity of producing two different proteins with completely distinct locations and functions in the plant. The researchers observed that in the root ZIFL1 codifies a protein that is important for the transport of auxin, a hormone essential for the correct growth and development of the plant. However, in the leaves the same gene originates a protein that promotes tolerance to drought. The gene presented in this study is one of the few identified to produce two proteins with such different biological roles.

Related Articles


ZIFL1 belongs to a family of transporter genes known to be present in all classes of organisms, but the functional role of most of its members remains unknown. What is known is that these transporter genes encode proteins that are integrated into cell membranes and act by allowing the passage of small molecules across them. By undergoing genetic and cell biology studies in the plant model Arabidopsis thaliana, Paula Duque's team was able to study the role of the ZIFL1 gene. What surprised the scientists was that mutant plants unable to produce the ZIFL1 transporter presented specific defects in different organs and functions. On one hand, their roots exhibited problems of growth, ramification and orientation when compared to normal plants.

These observations suggested that the ZIFL1 gene was involved in the transport of the auxin hormone, which plays an important role in the development of the root. But the researchers also found out that the mutant plants had problems in tolerating drought. They realized that the leaf pores that regulate transpiration -- the stomata -- were more open in the mutants than in normal plants, resulting in the loss of higher quantities of water. This suggested a role for ZIFL1 in the closure of stomata and in the control of water loss by the plant, which can be critical under drought conditions.

Intrigued by these observations, the researchers investigated whether the ZIFL1 gene could be originating two proteins that would act differently in distinct tissues. Alternative splicing is a key mechanism allowing the same gene to produce multiple proteins. When genes are activated to give rise to proteins, they first originate an intermediate molecule of RNA that can be processed differently, with some parts being removed. This cut and paste process may originate different RNA molecules that can then be converted into different proteins. Estelle Remy, investigator at Duque's laboratory and first author of this work, observed that in the case of the ZIFL1 gene, alternative splicing originates two RNA molecules that differ in just two chemical residues. However, this small difference has a huge impact on the proteins that are generated, with one of them being shortened by 67 amino acids. In collaboration with Isabel Sá-Correia's group  at Instituto Superior Técnico, the researchers then tested the activity of the two proteins in yeast cells and found that both transport potassium ions.

Having different size but similar transport activity, Estelle looked for the reason why these two proteins had such distinct biological functions. Surprisingly, she observed that root tissues only present the longer form of the protein, whereas the shorter protein can only be found in the leaves. Furthermore, the location of these two proteins also differs inside the cells of the root and leaves, being integrated into different cell membranes. According to Estelle, "the fact that we cannot find both proteins being expressed either in roots or leaves suggests that these tissues may have specific factors that somehow influence the splicing of the ZIFL1 RNA into the form that confers the biological role necessary for that tissue."

Says Paula Duque, "To our knowledge, there are not many known cases of proteins with such different biological functions being codified by the same gene. What is most fascinating is how the inclusion or removal of just two chemical residues in the RNA molecule results in the production of two proteins that play essential roles either in hormone transport or in tolerance to drought."

Alternative splicing is a crucial mechanism to generate protein diversity. In humans, about 20,000 to 25,000 genes codify proteins. However, recent studies indicate that over 90% of these genes undergo alternative splicing, with scientists estimating that there may be up to 500,000 or more different proteins in the human body.

This study was carried out at the IGC in collaboration with the research groups of Isabel Sá-Correia (Biological Sciences Research Group, IBB/CEBQ, Instituto Superior Técnico, Portugal) and Jiří Friml (VIB/Ghent University, Belgium and Institute of Science and Technology, Austria). It was funded by Fundação para a Ciência e a Tecnologia (Portugal).


Story Source:

The above story is based on materials provided by Instituto Gulbenkian de Ciência (IGC). Note: Materials may be edited for content and length.


Journal Reference:

  1. E. Remy, T. R. Cabrito, P. Baster, R. A. Batista, M. C. Teixeira, J. Friml, I. Sa-Correia, P. Duque. A Major Facilitator Superfamily Transporter Plays a Dual Role in Polar Auxin Transport and Drought Stress Tolerance in Arabidopsis. The Plant Cell, 2013; DOI: 10.1105/tpc.113.110353

Cite This Page:

Instituto Gulbenkian de Ciência (IGC). "When a gene is worth two: Same gene fulfills different biological roles in plants." ScienceDaily. ScienceDaily, 22 March 2013. <www.sciencedaily.com/releases/2013/03/130322154124.htm>.
Instituto Gulbenkian de Ciência (IGC). (2013, March 22). When a gene is worth two: Same gene fulfills different biological roles in plants. ScienceDaily. Retrieved December 21, 2014 from www.sciencedaily.com/releases/2013/03/130322154124.htm
Instituto Gulbenkian de Ciência (IGC). "When a gene is worth two: Same gene fulfills different biological roles in plants." ScienceDaily. www.sciencedaily.com/releases/2013/03/130322154124.htm (accessed December 21, 2014).

Share This


More From ScienceDaily



More Plants & Animals News

Sunday, December 21, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Researchers Test Colombian Village With High Alzheimer's Rates

Researchers Test Colombian Village With High Alzheimer's Rates

AFP (Dec. 19, 2014) — In Yarumal, a village in N. Colombia, Alzheimer's has ravaged a disproportionately large number of families. A genetic "curse" that may pave the way for research on how to treat the disease that claims a new victim every four seconds. Duration: 02:42 Video provided by AFP
Powered by NewsLook.com
Monarch Butterflies Descend Upon Mexican Forest During Annual Migration

Monarch Butterflies Descend Upon Mexican Forest During Annual Migration

Reuters - Light News Video Online (Dec. 19, 2014) — Millions of monarch butterflies begin to descend onto Mexico as part of their annual migration south. Rough Cut (no reporter narration) Video provided by Reuters
Powered by NewsLook.com
The Best Protein-Filled Foods to Energize You for the New Year

The Best Protein-Filled Foods to Energize You for the New Year

Buzz60 (Dec. 19, 2014) — The new year is coming and nothing will energize you more for 2015 than protein-filled foods. Fitness and nutrition expert John Basedow (@JohnBasedow) gives his favorite high protein foods that will help you build muscle, lose fat and have endless energy. Video provided by Buzz60
Powered by NewsLook.com
Birds Might Be Better Meteorologists Than Us

Birds Might Be Better Meteorologists Than Us

Newsy (Dec. 19, 2014) — A new study suggests a certain type of bird was able to sense a tornado outbreak that moved through the U.S. a day before it hit. Video provided by Newsy
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
 
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:  

Breaking News:

Strange & Offbeat Stories

 

Plants & Animals

Earth & Climate

Fossils & Ruins

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:  

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile iPhone Android Web
Follow Facebook Twitter Google+
Subscribe RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins