Intermediate product with an important function

PI49 membrane lipid regulates cells

Researchers from the University of Cambridge (England) and Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU) have proved that the membrane lipid PI4P plays a more significant role in regulating the inside of the cell membrane than previously thought. The results have now been published in the scientific journal ‘Science’.

Cell membranes separate the inside of the cell from the external environment. They control the exchange of substances via signalling pathways and thus also the internal composition of the cell. These signalling pathways are, for instance, used to control the heart contractions or to release insulin.

Anions in the cell membrane – such as Phosphatidylinositol-4,5-Bisphosphat [PI(4,5)P₂], play an important role in receiving signals to the cell. When manufacturing PI(4,5)P₂ PI4P is also produced which is a membrane lipid that was previously only thought to be an intermediate product.

A research group led by Professor Robin Irvine from the University of Cambridge demonstrated a clear difference in the function of both substances in their experiments. Chemical bonds were discovered which interact with predominantly one of the two membrane lipids. In the experiments, the researchers demonstrated that the production of PI(4,5)P₂ is less dependent on P14P than previously assumed. Evidence was also found suggesting that P14P can assume at least some of the functions of PI(4,5)P₂.

The FAU researcher Dr. Michael Fischer provided an important contribution to the experiments conducted by Dr. Gerald Hammond: some ion channels in the cell membrane that transfer temperature and pain sensations need PI(4,5)P₂ and PI4P to function correctly. An unexpected discovery during the experiment was that both membrane lipids have different functions in this process. “It seems that the regulation function of both substances is more autonomous than we had previously assumed,” explains Michael Fischer.

The breakthrough means that these substances could be influenced selectively and be harnessed in the development of new medicines. However, as so many physiological functions are regulated by PI(4,5)P₂ and PI4P, additional research is necessary to explore further practical applications. The results were published in the international science journal ‘Science’ (DOI: 10.1126/science.1222483).

Further information for the press:

uni | media service | research No. 28/2012 on 19.7.2012