Membrane-coat proteins: Bacteria have them too

Jan 20, 2010
This electron microscopy image shows Gemmata obscuriglobus. This and other PVC bacteria, the EMBL scientists discovered, have membrane-coat proteins associated with the membranes of sub-cellular compartments like the one shown in green, in which vesicles can be seen as dark green regions. The bacterium's DNA is colored purple. Credit: Rachel Melwig & Christine Panagiotidis / EMBL

Although they are present almost everywhere, on land and sea, a group of related bacteria in the superphylum Planctomycetes-Verrucomicrobia-Chlamydiae, or PVC, have remained in relative obscurity ever since they were first described about a decade ago.

Scientists at the European Molecular Biology Laboratory (EMBL) in Heidelberg, Germany, have discovered that these poorly-studied possess proteins thought to exist only in eukaryotes - organisms whose cells have a nucleus. Their findings, featured on the cover of today's edition of PLoS Biology, could help to unravel part of the evolutionary history of eukaryotic cells such as our own.

In eukaryotes, the endomembrane system is a network of membrane-bound compartments which stores and transports material within the cell. These compartments, which include organelles such as the and the Golgi complex, also exchange portions of membrane with each other, by forming and absorbing vesicles. Scientists believed that membrane-bound compartments were unique to , and that membrane-coat proteins, which have a unique architecture and are associated with the endomembrane system, existed only in eukaryotes. Recently, however, membrane-bound compartments were observed in PVC bacteria.

In the new study, researchers in the group of Iain Mattaj, Director General of EMBL, are the first to provide molecular evidence that the coat proteins that shape the eukaryotic endomembrane system also exist in prokaryotes. Using a combination of bioinformatics, molecular biology and , the EMBL scientists found that proteins with the characteristic membrane-coat architecture also exist in members of the PVC group, but not in any other bacteria, in association with the membranes of subcellular compartments.

"Our findings provide unexpected clues as to how the endomembrane system of eukaryotes evolved," says Damien Devos, who led the study, "and since they are relatively simple cells, these bacteria could be used as model organisms for studying how this system works."

Explore further: Researchers successfully clone adult human stem cells

add to favorites email to friend print save as pdf

Related Stories

Simplest bacteria unravelled at the cellular level

Dec 28, 2009

Even the simplest cell appears to be far more complex than researchers had imagined. In a series of three articles in the journal Science, researchers including Vera van Noort at the European Molecular Biology Laboratory (EMBL) ...

Study: How an internal organelle doubles

Nov 07, 2005

Yale University scientists have found a mechanism that regulates the way an internal organelle, the Golgi apparatus, duplicates as cells prepare to divide.

Recommended for you

Researchers successfully clone adult human stem cells

19 hours ago

(Phys.org) —An international team of researchers, led by Robert Lanza, of Advanced Cell Technology, has announced that they have performed the first successful cloning of adult human skin cells into stem ...

Researchers develop new model of cellular movement

22 hours ago

(Phys.org) —Cell movement plays an important role in a host of biological functions from embryonic development to repairing wounded tissue. It also enables cancer cells to break free from their sites of ...

For resetting circadian rhythms, neural cooperation is key

Apr 17, 2014

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 ...

User comments : 0

More news stories

Researchers successfully clone adult human stem cells

(Phys.org) —An international team of researchers, led by Robert Lanza, of Advanced Cell Technology, has announced that they have performed the first successful cloning of adult human skin cells into stem ...

Male monkey filmed caring for dying mate (w/ Video)

(Phys.org) —The incident was captured by Dr Bruna Bezerra and colleagues in the Atlantic Forest in the Northeast of Brazil.  Dr Bezerra is a Research Associate at the University of Bristol and a Professor ...

Researchers develop new model of cellular movement

(Phys.org) —Cell movement plays an important role in a host of biological functions from embryonic development to repairing wounded tissue. It also enables cancer cells to break free from their sites of ...

Health care site flagged in Heartbleed review

People with accounts on the enrollment website for President Barack Obama's signature health care law are being told to change their passwords following an administration-wide review of the government's vulnerability to the ...

Airbnb rental site raises $450 mn

Online lodging listings website Airbnb inked a $450 million funding deal with investors led by TPG, a source close to the matter said Friday.