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: Tarantula toxin is used to report on electrical activity in live cells

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

Scientists see how plants optimize their repair

11 hours ago

Researchers led by a Washington State University biologist have found the optimal mechanism by which plants heal the botanical equivalent of a bad sunburn. Their work, published in the Proceedings of the Na ...

Structure of an iron-transport protein revealed

18 hours ago

For the first time, the three dimensional structure of the protein that is essential for iron import into cells, has been elucidated. Biochemists of the University of Zurich have paved the way towards a better ...

Over-organizing repair cells set the stage for fibrosis

18 hours ago

The excessive activity of repair cells in the early stages of tissue recovery sets the stage for fibrosis by priming the activation of an important growth factor, according to a study in The Journal of Ce ...

User comments : 0