Membrane protein families, encompassing voltage-sensitive representatives. The families are arranged in four large groups according to Almén et al. (2009); only α-helical membrane proteins are shown. Channels are subdivided in voltage-gated (VGIC), ligand-gated (LGICs), chloride channels and aquaporins. Blue indicates families containing voltage-sensitive membrane proteins, and white indicates families in which voltage-sensitive representatives have not yet been discovered. The families shown in red correspond to membrane proteins for which changes in the MP is the primary stimulus for activation. Finally, the families in orange contain membrane proteins whose voltage sensitivity is controversial. To compose this figure we used data from multiple references (Nakao and Gadsby, 1986; Catterall, 1988; Weer et al., 1988; Colombini, 1989; Schnetkamp and Szerencsei, 1991; Bernardi, 1992; Parent et al., 1992; Kavanaugh, 1993; Petronilli et al., 1994; Jentsch et al., 1995; Reddy et al., 1995; Wadiche et al., 1995; Beltrán et al., 1996; Caterina et al., 1997; Halestrap et al., 1997; Scorrano et al., 1997; Cooper et al., 1998; Kaim and Dimroth, 1998, 1999; Künkele et al., 1998; Lostao et al., 2000; Sugawara et al., 2000; Yao et al., 2000; Zheng et al., 2000; Ben-Chaim et al., 2003; DeCoursey et al., 2003; Jutabha et al., 2003, 2011; Mackenzie et al., 2003; Melzer et al., 2003; Bezanilla, 2005, 2008; Valdez and Boveris, 2007; Anzai et al., 2008; Hub et al., 2010; Zhang et al., 2011; Bargiello et al., 2012; Malhotra et al., 2013; Rinne et al., 2013; van der Laan et al., 2013; Zander et al., 2013; Rosasco et al., 2015; Vorburger et al., 2016).