We are interested in the biological function of globin family proteins at the molecular level. The objective is to assess the impact of physicochemical and biochemical parameters on their structure. We also explore the role of neuroglobin in the survival of cancer cells through integrated approaches in biochemistry and cellular biology.

About twenty years ago, several globins were discovered (cytoglobin, neuroglobin, globin X, rice hemoglobin), all with three-dimensional structures similar to known globins (hemoglobin and myoglobin). The most intriguing is probably neuroglobin, expressed in the brain and belonging to a branch of globins that diverged very early in evolution. Despite a wealth of literature, there is no consensus on its function. It may act as an O2 sensor, promote the survival of healthy (neuronal) or cancer cells, or detoxify reactive oxygen and nitrogen species. Our work focuses on several of these new globins at both molecular and cellular levels.

We have developed a research focus on the reactivity of hexacoordinate globins with hydrogen peroxide, a molecule associated with oxidative stress, studied by time-resolved spectroscopy (stopped flow) using site-directed mutagenesis [Derrien2023]. A first part of our activity focuses on rice hemoglobin and the phenomenon of tyrosine dimerization that results from this peroxidase activity. In addition to these studies, we have collaborated since 2009 with Jaroslava Miksovska (Florida International University, USA) [Tangar2019, Butcher2018, Estevez2020]. We specifically study globin X, which has increased stability with respect to pH compared to other globins [Farhana2022].

Structure of Human Neuroglobin (pdb 1OJ6) (made with VMD software)

Breast cancer cell line (MCF-7) after incubation with Alexa-488 labeled human neuroglobin. In green: internalized Alexa-488 labeled neuroglobin. In red: plasma membranes (CellMask) and in blue: nuclei (Hoechst). Image obtained by spinning disk confocal microscopy (Imagerie-Gif platform).