Table 2. Changes in HV1 properties in N-terminal (1–100) mutants versus WT channels .
| Mutant | Species | Expr. system | I? | τ act | τ tail | ΔV thr | ΔpH slope | Selectivity | Other | Reference |
|---|---|---|---|---|---|---|---|---|---|---|
| hHV1S | LK35.2 wc | Yes | 2.5 | 0.75 | 5.4 | 43.2 | H+ | More profound enhanced gating | Hondares et al., 2014 | |
| T9A | hHV1S | LK35.2 pp | Yes | 0.28 | 0.9 | −18.2 | Enhanced gating lost | Hondares et al., 2014 | ||
| S77A | hHV1S | LK35.2 pp | Yes | 1.75 | 1.1 | −3.6 | nc | Hondares et al., 2014 | ||
| T9A/S77A | hHV1S | LK35.2 pp | Yes | 0.63 | 0.8 | −5.8 | Enhanced gating lost | Hondares et al., 2014 | ||
| T29A | hHV1 | LK35.2 pp | Yes | 0.23 | 1.8 | −27.6 | Enhanced gating lost | Musset et al., 2010a | ||
| T29D | hHV1 | LK35.2 pp | Yes | 0.41 | 1.0 | −12.5 | Enhanced gating lost | Musset et al., 2010a | ||
| M91T | hHV1 | COS wc | Yes | 20 | 47 | First identified naturally occurring hHV1 mutation | Iovannisci et al., 2010 | |||
| S97A | hHV1 | LK35.2 pp | Yes | 0.96 | 1.2 | 3.9 | nc | Musset et al., 2010a | ||
| S97D | hHV1 | LK35.2 pp | Yes | 0.34 | 0.9 | −3.0 | nc | Musset et al., 2010a | ||
| T29A/S97A | hHV1 | LK35.2 pp | Yes | 0.25 | 1.7 | −19.4 | Enhanced gating lost | Musset et al., 2010a | ||
| S98A | hHV1 | HEK wc | Yes | −7 | Ramsey et al., 2010 | |||||
| H99A | hHV1 | HEK wc | Yes | 13 | Ramsey et al., 2010 | |||||
| R100A | hHV1 | HEK wc | Yes | −7 | Ramsey et al., 2010 | |||||
| ΔN (1–96 deleted) | hHV1 | HEK wc | Yes | 15 | 40 | Ramsey et al., 2010 | ||||
| ΔN/ΔC | mHV1 (1–77 deleted, V216stop) | HEK wc | Yes | 0.20 | nc | nc | Loss of dimer formation | Koch et al., 2008 | ||
| ΔN/ΔC | mHV1 (1–77 deleted, V216stop) | HEK i-o | Yes | Weaker Zn2+ effects | Musset et al., 2010b |
That numerical entries are shown does not imply that any given change was significant. The entries for hHV1S are in a short isoform and are compared with full-length hHV1. HEK, HEK-293, HEK-293T, tsA, or HM1; COS, COS-7; pp, perforated patch; wc, whole cell; i-o, inside-out patch configuration. 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 ΔVthreshold value is the change in absolute position of the gH–V relationship versus WT. The ΔpH slope is the slope in millivolts of the relationship between Vthreshold (or other parameters reflecting the absolute position of the gH–V relationship) and Vrev or EH (which are not identical; see section Table entries defined). When C-terminal truncations (ΔC) are indicated as XNNNstop, this means STOP replaces X at position NNN; hence, position NNN and all subsequent residues are truncated, and the last position remaining is NNN-1. The mouse N-terminal deletions (ΔN) were done by replacing P78M to initiate translation at that position.