Anna Maria Marini
Rh factors and the control of membrane permeability to ammonium
cancer • cellular biology • molecular transport
Anna Maria Marini is a Senior Research Associate at the FNRS. Her work at the Institute for Biology and Molecular Medicine (Université libre de Bruxelles) is dedicated to the transport of ammonium ions ( (NH4+) and the role this transport plays in various physiological and pathological contexts. Ammonium ions are a major source of nitrogen for microorganisms and plants. In animals, it is primarily described as a pH regulator and toxic waste . In recent years, Anna Maria Marini and her team have been able to demonstrate that ammonium is much more than metabolic waste. It can promote cell proliferation, in particular by stimulating the TOR signalling pathway, which is important for controlling growth and metabolism.
The early years of the project made it possible to develop our understanding of the molecular mechanism that allows ammonium to cross biological membranes, thanks to transport proteins from the “Mep-Amt-Rh” family, to which the human Rh (Rhesus) factors belong. By deprotonating the ammonium ion during its translocation, these proteins acquire a specificity that allows them to differentiate between the ammonium ion and the potassium ion (with an identical charge and similar size). The next two years will make it possible to develop tools that can target the activity of Rh factors, in order to study the impact of their activation or inactivation.