The complexity of regulated development in plants

March 15, 2013
Four Arabidopsis FBX proteins (green, top and bottom rows) preferentially accumulate in speckled structures in the cytoplasm of protoplasts in leaves, outside of chloroplasts (red, middle and bottom rows). Credit: Kuroda et al.

In most living organisms, growth and development are controlled by selective modification of the lifespans of particular proteins. This mechanism is especially prevalent in plants, allowing rapid moderation of gene expression. Even the relatively streamlined Arabidopsis genome encodes more than 1,400 components of ubiquitin ligase complexes—molecular machines that are each able to single out a specific type of protein for degradation while sparing tens of thousands of others. However, the selectivity with which these hundreds of components assemble to form complexes has yet to be defined.

A team led by Minami Matsui from the Plant Functional Genomics Research Group at the RIKEN Plant Science Center has now begun to explore the diversity of the largest group of plant ubiquitin ligases—the SCF complexes—in Arabidopsis. Each plant SCF complex comprises four components, two of which are an ASK and an FBX protein. The Arabidopsis genome encodes an estimated 897 FBX and 21 ASK proteins. In their most recent work, the researchers investigated the locations of selected FBX and ASK proteins and their ability to interact with each other1.

Knowing the locations of proteins is equally as important as understanding their interaction, says Yuki Yanagawa from the research team. "After all, even if two proteins are capable of physical interaction, that's irrelevant in physiological terms if the proteins are found in different tissues or subcellular compartments."

The team used a yeast-based assay to map the physical affinities of each of the 341 Arabidopsis FBX proteins for each of the 19 ASK proteins. More than half the FBX proteins didn't interact with any of the ASK proteins tested, suggesting other components, SCF complexes or post-translational modifications might be needed to facilitate certain FBX–ASK interactions. A complementary experiment suggested, however, that the original assay may also have underestimated the capacities of certain FBX proteins to interact with ASKs.

Explore further: Cracking the plant-cell membrane code

More information: Kuroda, H. et al. A comprehensive analysis of interaction and localization of Arabidopsis SKP1-LIKE (ASK) and F-Box (FBX) Proteins. PLoS One 7, e50009 (2012).

Related Stories

Cracking the plant-cell membrane code

March 22, 2010

( -- To engineer better, more productive crops and develop new drugs to combat disease, scientists look at how the sensor-laden membranes surrounding cells control nutrient and water uptake, secrete toxins, and ...

Boon to plant science

August 30, 2010

In both plant and animal cells, protein activity is often regulated by phosphorylation, by which a phosphate group is added to one or more sites on a protein. A team led by Ken Shirasu of RIKEN Plant Science Center, Yokohama, ...

Discovery identifies elaborate G-protein network in plants

April 21, 2011

The most elaborate heterotrimeric G-protein network known to date in the plant kingdom has been identified by Dr. Sona Pandey, principal investigator at the Danforth Plant Science Center. The results of this research are ...

Putting light-harvesters on the spot

October 19, 2011

How the light-harvesting complexes required for photosynthesis get to their site of action in the plant cell is reported by RUB biologists in the Journal of Biological Chemistry. The team led by Prof. Dr. Danja Schunemann ...

Recommended for you

Fecal mimicry found in seeds that fool dung beetles

October 6, 2015

(—A team of researchers with the University of Cape Town and the University of KwaZulu-Natal, both in South Africa, has found an example of a seed from a plant using mimicry to fool a beetle. In their paper published ...

A better way to read the genome

October 9, 2015

UConn researchers have sequenced the RNA of the most complicated gene known in nature, using a hand-held sequencer no bigger than a cell phone.


Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.