Freeze! A protein group affecting lipid dynamics at cell membranes discovered

Sep 23, 2013
BAR proteins can create stable lipid microdomains at cell membranes. Credit: Hongxia Zhao

Eukaryotic cells are compartmentalized by membranes, whose shape and dynamics are precisely regulated to maintain their correct functions. Consequently, many cellular processes such as endocytosis, migration and morphogenesis rely on proteins that bind directly to membranes and sculpt them into desired shapes.

BAR domain proteins are among the central membrane-sculpting proteins in all eukaryote cells. Studies by Pekka Lappalainen laboratory at Institute of Biotechnology, University of Helsinki, Finland, now reveal that BAR domain proteins not only bend membranes, but also generate extremely stable lipid microdomains by inhibiting the lateral diffusion of certain lipids nearly completely.

In a new study published in Cell Reports, Hongxia Zhao working in the Lappalainen laboratory discovered that all BAR domain proteins induce strong clustering of phosphoinositides, which are important lipids involved in regulating and cellular signalling.

Her studies also revealed that BAR domains assemble into extremely stable scaffolds on the membrane. Surprisingly, mobility of phosphoinositides was nearly completely frozen in these BAR domain induced lipid platforms. These extremely stable protein-lipid scaffolds may contribute to diverse by generating lipid at the tips of the BAR domain scaffolds. Furthermore, the membrane microdomains induced by BAR domains are expected to function as diffusion barriers, which may for example trap membrane-associated receptor and cargo molecules at the endocytic bud.

Thus, distribution and mobility of specific lipid species at the appears to precisely regulated by membrane-associated proteins. Hongxia Zhao is now continuing studies on regulation of lipid dynamics as an Academy Research Fellow at University of Helsinki.

Explore further: Membranes contain beautiful patterns—but their function is a mystery

add to favorites email to friend print save as pdf

Related Stories

Chemists get grip on slippery lipids

Aug 30, 2007

The ability of the body's cells to correctly receive and convey signals is crucial to good health. Lipids, or fats, play a critical role in this regulation by providing spaces for proteins to gather and network. They are ...

Proteins hoist the anchor

Aug 05, 2013

Researchers from the Ruhr-Universität Bochum (RUB) and from the MPI Dortmund have for the first time successfully reproduced the recycling process of proteins regulating cellular transport in a biophysical ...

Recommended for you

Researchers discover new strategy germs use to invade cells

7 hours ago

The hospital germ Pseudomonas aeruginosa wraps itself into the membrane of human cells: A team led by Dr. Thorsten Eierhoff and Junior Professor Dr. Winfried Römer from the Institute of Biology II, members of the Cluster ...

Progress in the fight against harmful fungi

7 hours ago

A group of researchers at the Max F. Perutz Laboratories has created one of the three world's largest gene libraries for the Candida glabrata yeast, which is harmful to humans. Molecular analysis of the Candida ...

How steroid hormones enable plants to grow

Aug 19, 2014

Plants can adapt extremely quickly to changes in their environment. Hormones, chemical messengers that are activated in direct response to light and temperature stimuli help them achieve this. Plant steroid ...

Surviving the attack of killer microbes

Aug 19, 2014

The ability to find food and avoid predation dictates whether most organisms live to spread their genes to the next generation or die trying. But for some species of microbe, a unique virus changes the rules ...

Histones and the mystery of cell proliferation

Aug 19, 2014

Before cells divide, they create so much genetic material that it must be wound onto spools before the two new cells can split apart. These spools are actually proteins called histones, and they must multiply ...

User comments : 0