Mechanosensitive PANX1 activity is modulated by stomatin in human Red Blood Cells

ROUGE SARAH; GENETET SANDRINE; LEAL DENIS, MARIA FLORENCIA; DUSSIOT MICHAEL; SCHWARZBAUM PABLO JULIO; OSTUNI, MARIANO; LUCÍA CANÉ, SANDRINE GENETET, ISABELLE MOURE-CHANTELOUP, MARIANO OSTUNI, PABLO SCHWARZBAUM AND VANESA HERLAX

INTERNATIONAL JOURNAL OF MOLECULAR SCIENCES

MOLECULAR DIVERSITY PRESERVATION INTERNATIONAL-MDPI

Lugar: Basel; Año: 2022

1422-0067

Abstract: Pannexin 1 (PANX1) was proposed to drive ATP release from red 10 blood cells (RBCs) in response to stress conditions. Stomatin, a membrane pro-11 tein regulating mechanosensitive channels, has been proposed to modulate 12 PANX1 activity in non-erythroid cells. To determine whether stomatin modu-13 lates PANX1 activity in an erythroid context, we have i) assessed the in situ sto-14 matin-PANX1 interaction in RBCs, 2) measured PANX1 stimulated-activity in 15 RBCs expressing stomatin or from OverHydrated Hereditary Stomatocytosis 16 (OHSt) patients lacking stomatin, and in erythroid K562 cells invalidated for 17 stomatin. Proximity Ligation Assay coupled with flow imaging show 27.09% and 18 6.13% positive events in control and OHSt RBCs, respectively. The uptake of 19 dyes 5(6)-Carboxyfluorescein (CF) and TO-PRO-3 was used to evaluate PANX1 20 activity. RBCs permeability for CF is 34% and 11.8% in control and OHSt RBCs, 21 respectively. PANX1 permeability for TO-PRO-3 is 35.72% and 18.42% in K562 22 stom+ and stom- clones, respectively. These results suggest an interaction be-23 tween PANX1 and stomatin in the human RBCs and show a significant defect in 24 PANX1 activity in the absence of stomatin. Based on these results, we propose 25 that stomatin plays a major role in the opening of the PANX1 pore by being in-26 volved in a caspase-independent lifting of autoinhibition.