Fyn specifically Regulates the activity of red cell glucose-6-phosphate-dehydrogenase
Matte’ Alessandro,
Lupo Francesca,
Tibaldi Elena,
Di Paolo Maria Luisa,
Federti Enrica,
Andrea Carpentieri,
Piero Pucci,
Brunati Anna Maria,
Cesaro Luca,
Turrini Francesco,
Gomez Manzo Saul,
Soo Young Choi,
Marcial Quino Jaime,
Kim Dae Won,
Antonella Pantaleo,
Xiuli An,
Iana Iatcenko,
Cappellini Maria Domenica,
Forni Gian Luca,
De Franceschi Lucia
Affiliations
Matte’ Alessandro
Dept of Medicine University of Verona and AOUI Verona, Verona, Italy
Lupo Francesca
Dept of Medicine University of Verona and AOUI Verona, Verona, Italy
Tibaldi Elena
Dept of Molecular Medicine, University of Padua, Padua, Italy
Di Paolo Maria Luisa
Dept of Molecular Medicine, University of Padua, Padua, Italy
Federti Enrica
Dept of Medicine University of Verona and AOUI Verona, Verona, Italy
Andrea Carpentieri
Dept of Chemical Sciences, University Federico II, Naples, Italy
Piero Pucci
Dept of Chemical Sciences, University Federico II, Naples, Italy
Brunati Anna Maria
Dept of Molecular Medicine, University of Padua, Padua, Italy
Cesaro Luca
Dept of Molecular Medicine, University of Padua, Padua, Italy
Turrini Francesco
Dept of Oncology, University of Torino, Torino, Italy
Gomez Manzo Saul
Laboratorio de Bioquímica Genética, Instituto Nacional de Pediatría, Secretaría de Salud, Mexico City, Mexico
Soo Young Choi
Institute of Bioscience and Biotechnology, Hallym University, Gangowo-do, South Korea
Marcial Quino Jaime
Consejo Nacional de Ciencia y Tecnology, Instituto Nacional de Pediatría, Secretaría de Salud, Mexico City, Mexico
Kim Dae Won
Institute of Bioscience and Biotechnology, Hallym University, Gangowo-do, South Korea
Antonella Pantaleo
Dept of Physiology, University of Sassari, Sassari, Italy
Xiuli An
School of Life Sciences, Zhengzhou University, Zhengzhou, China; Laboratory of Membrane Biology, New York Blood Center, New York, NY, USA
Iana Iatcenko
Dept of Medicine University of Verona and AOUI Verona, Verona, Italy
Cappellini Maria Domenica
Dept of Medicine, University of Milan, Milan, Italy
Forni Gian Luca
Centro Della Microcitemia e Delle Anemie Congenite, Ospedale Galliera, Genova, Italy
De Franceschi Lucia
Dept of Medicine University of Verona and AOUI Verona, Verona, Italy; Corresponding author. Dept of Medicine, University of Verona and AOUI Verona, P.Le L. Scuro, 10, 37134, Verona, Italy.
Fyn is a tyrosine kinase belonging to the Src family (Src-Family-Kinase, SFK), ubiquitously expressed. Previously, we report that Fyn is important in stress erythropoiesis. Here, we show that in red cells Fyn specifically stimulates G6PD activity, resulting in a 3-fold increase enzyme catalytic activity (kcat) by phosphorylating tyrosine (Tyr)-401. We found Tyr-401 on G6PD as functional target of Fyn in normal human red blood cells (RBC), being undetectable in G6PD deficient RBCs (G6PD-Mediterranean and G6PD-Genova). Indeed, Tyr-401 is located to a region of the G6PD molecule critical for the formation of the enzymatically active dimer. Amino acid replacements in this region are mostly associated with a chronic hemolysis phenotype. Using mutagenesis approach, we demonstrated that the phosphorylation status of Tyr401 modulates the interaction of G6PD with G6P and stabilizes G6PD in a catalytically more efficient conformation. RBCs from Fyn-/−mice are defective in G6PD activity, resulting in increased susceptibility to primaquine-induced intravascular hemolysis. This negatively affected the recycling of reduced Prx2 in response to oxidative stress, indicating that defective G6PD phosphorylation impairs defense against oxidation. In human RBCs, we confirm the involvement of the thioredoxin/Prx2 system in the increase vulnerability of G6PD deficient RBCs to oxidation. In conclusion, our data suggest that Fyn is an oxidative radical sensor, and that Fyn-mediated Tyr-401 phosphorylation, by increasing G6PD activity, plays an important role in the physiology of RBCs. Failure of G6PD activation by this mechanism may be a major limiting factor in the ability of G6PD deficient RBCs to withstand oxidative stress.
