Scientists at Imperial College London have identified four new proteins that act as receptors for an essential signalling molecule in bacteria such as MRSA.
The receptors are thought to play an important role in enabling bacteria to respond to their environment. Their discovery provides scientists with vital clues in the hunt for new antibiotics, which are increasingly in need as bacteria become resistant to existing treatments.
The bacterium Staphylococcus aureus causes life-threatening diseases in hospital patients and in previously healthy people. Methicillin-resistant S. aureus strains, known as MRSA, are especially difficult to treat due to their antibiotic resistance.
Scientists are eager to understand the chemical processes that allow bacteria to respond to changes in their environment. Interfering with these processes could help prevent bacteria from surviving inside the human body.
A recently discovered molecule called c-di-AMP appears to play a vital role as a messenger in many bacteria, carrying signals between parts of the cell. There is evidence that strains with more c-di-AMP are more resistant to antibiotics. But until now, very little was known about what processes in cells are regulated by c-di-AMP.
"What makes this molecule special and a bit different from others like it is that there is now growing evidence that many bacteria need to produce this molecule in order to grow and divide, so it's an essential component of the cell," said Dr Angelika Gr-ndling from the MRC Centre for Molecular Bacteriology and Infection at Imperial College London, who led the new study in collaboration with Dr Vincent Lee from the University of Maryland USA.
Signalling molecules work by binding to specific receptor proteins, which act as switches for cellular functions. "So the real key to understanding what pathways are controlled by c-di-AMP, and therefore help us to understand why this molecule is important for the growth of bacteria, is to find these target proteins," Dr Gr-ndling said.