Increased Environmental Carbon Levels -- The Good News!

Carbon levels are sensed by a biological molecule, adenylyl cyclase (AC), that can then affect sperm motility or the virulence of a dangerous human pathogen. So far, AC is the only signalling molecule known to directly respond to inorganic carbon. Dr Martin Cann presented this work at the Society for Experimental Biology Annual Main meeting at the University of Kent, Canterbury on April 3.

Dr Cann's group have been studying the effects of increased levels of inorganic carbon (Ci) on Pseudomonas aeruginosa, a pathogen that causes an array of infections in weakened patients and is renowned for being difficult to treat with antibiotics. They have found that increased levels of Ci inhibit an AC required for host cell invasion.

"This suggests that the bacterium's sensitivity to Ci could potentially make this detection pathway an attractive target for the development of new anti-bacterial drugs", says Cann. "In theory, if you could increase the amount of Ci available locally to P. aeruginosa then you could stop it infecting the host."

The AC-enzyme is also known to send a cascade of signals that regulate mammalian sperm motility in response to Ci -- a consequence that has implications for human reproduction, perhaps in the treatment of infertility.

Dr Cann is learning more about the role of AC in carbon-detection using cyanobacteria and will report that, in conditions of elevated environmental CO2, AC is essential for full cyanobacterial motility.