Table 5. Changes in H_V1 properties in S3 (166–188) and S3–S4 linker (189–196) mutants versus WT channels .

Mutant	Species	Expr. system	I?	τ act	τ tail	ΔV thr	ΔpH slope	Selectivity	Other	Reference
E164A/E171A	hHV1	HEK wc	Yes			−7				Ramsey et al., 2010
H167N/H168V/K169N	hHV1	HEK wc	Yes			−13	44			Ramsey et al., 2010
E171A/D174A	hHV1	HEK wc	Yes			−116	39			Ramsey et al., 2010
E171A	hHV1	Vesicle flux							Δ H+ fluxa	Letts, 2014
D174A	hHV1	HEK wc	Yes			−111	38			Ramsey et al., 2010
D174A	hHV1	Vesicle flux							Δ H+ fluxa	Letts, 2014
D174N	hHV1	HEK wc	Yes			−142	36			Ramsey et al., 2010
D174H	hHV1	HEK wc	Yes			−136	37			Ramsey et al., 2010
D174E	hHV1	HEK wc	Yes			−52	46			Ramsey et al., 2010
D174A	CiHV1 [D222A]	Xenopus TEVC	Yes			−111				Chamberlin et al., 2014
D174C/R205C	CiHV1 [D222C/R255C]	Xenopus TEVC	Yes			−95				Chamberlin et al., 2014
D174C/R208C	CiHV1 [D222C/R258C]	Xenopus TEVC	Yes			48				Chamberlin et al., 2014
V178A	hHV1	Xenopus i-o	Yes			−27				Hong et al., 2014
D112V/V178D	hHV1	COS/HEK wc	No							Morgan et al., 2013
S181A	hHV1	HEK wc	Yes			18	46			Ramsey et al., 2010
S181A	hHV1	Xenopus i-o	Yes			0				Hong et al., 2014
D112V/S181D	hHV1	COS/HEK wc	No							Morgan et al., 2013
F182A	hHV1	Xenopus i-o	Yes			−9				Hong et al., 2014
D185A	hHV1	HEK wc	Yes			58	47			Ramsey et al., 2010
D185M	hHV1	COS/HEK wc	Yes					H+		Musset et al., 2011
D185V	hHV1	COS/HEK wc	Yes			20b	43b	H+		Musset et al., 2011
D185A	hHV1	COS/HEK wc	Yes			42b	40b	H+		Musset et al., 2011
D185A	hHV1	Vesicle flux							nc H+ flux	Letts, 2014
D185N	hHV1	COS/HEK wc	Yes			36b	47b	H+		Musset et al., 2011
D185C	CiHV1 [D233C]	Xenopus TEVC	Yes			76				Chamberlin et al., 2014
E185C/R208C	CiHV1 [D233C/R258C]	Xenopus TEVC	Yes			4				Chamberlin et al., 2014
E192A/E196A	hHV1	HEK wc	Yes			13				Ramsey et al., 2010
H193A	hHV1	HEK wc	Yes					H+	39 × Kd Zn2+	Ramsey et al., 2006
H193A	hHV1	Vesicle flux							nc H+ flux	Letts, 2014
H140A/H193A	hHV1	HEK wc	Yes			−12	46	H+	2,000 × Kd Zn2+	Ramsey et al., 2006

That numerical entries are shown does not imply that any given change was significant. Italicized mutant entries from nonhuman species show the hH_V1 equivalent. In the Expression system column: HEK, HEK-293, HEK-293T, tsA, or HM1; COS, COS-7; Xenopus, Xenopus laevis oocyte; wc, whole cell; i-o, inside-out patch configuration; TEVC, two-electrode voltage clamp. Blank entries indicate that the parameter was not examined. nc, measured, but no change. Parameters are given relative to WT in each study. For I?, yes means currents are detectable. Time constants are ratios of mutant/WT. The ΔV_threshold value is the change in absolute position of the g_H–V relationship versus WT. The ΔpH slope is the slope in millivolts of the relationship between V_threshold (or other parameters reflecting the absolute position of the g_H–V relationship) versus V_rev or E_H (which are not identical; see section Table entries defined).

^aNormal initial H⁺ flux followed by recovery ascribed to leak induced in vesicles.

^bPreviously unpublished, analyzed from data for Musset et al. (2011).