Team finds new building block in cells

Aug 02, 2010

(PhysOrg.com) -- Zemer Gitai, an assistant professor of molecular biology at Princeton University, members of his laboratory, and scientists from the California Institute of Technology have published results in Nature Cell Biology of new research into how a metabolic enzyme in bacteria forms cytoplasmic filaments that affect bacterial cell shape.

The study was published online July 18.

Gitai describes the findings as follows:

"We have discovered that an enzyme that has a role in basic cellular metabolism (CtpS, the enzyme that makes the essential nucleotide CTP), also forms cytoskeletal filaments that can play a structural role in regulating cell shape.

"I'm very excited about this work since it changes a lot of our thinking about both metabolism and the cytoskeleton, and provides a clue about how the cytoskeleton might have evolved in the first place. The work connects two exciting areas of research: cell shape formation and metabolism.

"Cytoskeletal proteins serve as cellular building blocks, and the has long been thought to consist of just three canonical members: actin, tubulin, and intermediate filaments. By using a novel imaging-based screening approach, we found that the that makes CTP, CTP Synthase (CtpS), also plays a previously-unappreciated role as a cytoskeletal protein by polymerizing into filaments that regulate the cell shape of the curved bacterium Caulobacter crescentus.

"The CtpS protein is found in all from bacteria to humans, suggesting that this could be a widespread phenomenon. Consistent with this possibility, we found that the CtpS protein from an unrelated , E. coli, also forms cytoskeletal filaments. Excitingly, the E. coli protein could replace both the cell shape and metabolic functions of the Caulobacter protein.

"This demonstrates that rather than adapting CtpS for a new cell shape role, Caulobacter has adapted its cell shape machinery to take advantage of the conserved filament-forming properties of CtpS. This finding suggests a general pathway for how cytoskeletal proteins may have evolved: perhaps polymerization first came about for other non-structural reasons such as enzymatic regulation, and then once filaments were there, they could be co-opted for additional structural purposes."

Other Princeton researchers involved in this work included Michael Ingerson-Mahar, a Princeton graduate student in molecular biology, and John Werner, a postdoctoral research fellow at the University. Caltech authors included Grant Jensen and Ariane Breigel.

Explore further: For cells, internal stress leads to unique shapes

More information: The metabolic enzyme CTP synthase forms cytoskeletal filaments, Nature Cell Biology. DOI:10.1038/ncb2087

add to favorites email to friend print save as pdf

Related Stories

Using a light touch to measure protein bonds

Jun 30, 2008

MIT researchers have developed a novel technique to measure the strength of the bonds between two protein molecules important in cell machinery: Gently tugging them apart with light beams.

A budding role for a cellular dynamo

Feb 18, 2009

Actin, a globular protein found in all eukaryotic cells, is a workhorse that varies remarkably little from baker's yeast to the human body. Part of the cytoskeleton, actin assembles into networks of filaments that give the ...

An architectural plan of the cell

Mar 06, 2007

Like our body every cell has a skeleton that provides it with a shape, confers rigidity and protects its fragile inner workings. The cytoskeleton is built of long protein filaments that assemble into networks ...

Measuring protein movements with nanosecond resolution

Mar 15, 2010

Researchers at the Department of Chemistry at the Technische Universität München (TUM, Germany) have developed a method that allows the observation of local movements in proteins on a time scale of nanoseconds to microseconds. ...

Recommended for you

For resetting circadian rhythms, neural cooperation is key

6 hours ago

Fruit flies are pretty predictable when it comes to scheduling their days, with peaks of activity at dawn and dusk and rest times in between. Now, researchers reporting in the Cell Press journal Cell Reports on April 17th h ...

Rapid and accurate mRNA detection in plant tissues

7 hours ago

Gene expression is the process whereby the genetic information of DNA is used to manufacture functional products, such as proteins, which have numerous different functions in living organisms. Messenger RNA (mRNA) serves ...

For cells, internal stress leads to unique shapes

Apr 16, 2014

From far away, the top of a leaf looks like one seamless surface; however, up close, that smooth exterior is actually made up of a patchwork of cells in a variety of shapes and sizes. Interested in how these ...

User comments : 0

More news stories

Deadly human pathogen Cryptococcus fully sequenced

Within each strand of DNA lies the blueprint for building an organism, along with the keys to its evolution and survival. These genetic instructions can give valuable insight into why pathogens like Cryptococcus ne ...

Hackathon team's GoogolPlex gives Siri extra powers

(Phys.org) —Four freshmen at the University of Pennsylvania have taken Apple's personal assistant Siri to behave as a graduate-level executive assistant which, when asked, is capable of adjusting the temperature ...

Better thermal-imaging lens from waste sulfur

Sulfur left over from refining fossil fuels can be transformed into cheap, lightweight, plastic lenses for infrared devices, including night-vision goggles, a University of Arizona-led international team ...