Page 88.
In Table I of the original paper, the units of the low affinity site concentrations were incorrect. The corrected table appears below.
Ca2+ and Mg2+ Regulatory Mechanisms for Slo1 BK Channels
Mutation site . | Ion . | KD closed . | KD open . | Location . | V equivalenta . | References . |
|---|---|---|---|---|---|---|
| mV | ||||||
| High affinity | Ca2+ | |||||
| Ca2+ bowl | 3.5–4.5 μM | 0.6–2.0 μM | RCK2? | 60–80 | Schreiber and Salkoff, 1997; Bian et al., 2001; Braun and Sy, 2001; Bao et al., 2002; Xia et al., 2002 | |
| M513 | 3.5–3.8 μM | 0.8–0.9 μM | RCK1 | 70–80 | Bao et al., 2002 | |
| D362/D367 | 17.2 ± 4.0 μM | 4.6 ± 1.0 μM | RCK1 | 60–80 | Xia et al., 2002 | |
| D81 | S0–S1 | 10–30 | Braun and Sy, 2001 | |||
| Low affinity | Ca2+/Mg2+ | RCK1 | ∼60 | |||
| E374/E399 | Mg2+ | 60–70 | Shi et al., 2002 | |||
| Ca2+ | 4.1 ± 3.5 mM | 1.8 ± 1.2 mM | 50–70 | Xia et al., 2002 | ||
| 2.3–3.1 mM | 0.5–0.9 mM | 50–70 | Zhang et al., 2001 | |||
| Mg2+ | 9–22 mM | 2–6 mM | 70 | Zhang et al., 2001 | ||
| 15 mM | 3.6 mM | 75 | Shi and Cui, 2001 | |||
| High affinity | Ca2+ | |||||
| Δ896–903 + M513I | ∼125 | Bao et al., 2002 | ||||
| D(897–901)N + D362A/D367A | ∼140 | Xia et al., 2002 | ||||
| D895N + D81N | ∼80 | Braun and Sy, 2001 |
Mutation site . | Ion . | KD closed . | KD open . | Location . | V equivalenta . | References . |
|---|---|---|---|---|---|---|
| mV | ||||||
| High affinity | Ca2+ | |||||
| Ca2+ bowl | 3.5–4.5 μM | 0.6–2.0 μM | RCK2? | 60–80 | Schreiber and Salkoff, 1997; Bian et al., 2001; Braun and Sy, 2001; Bao et al., 2002; Xia et al., 2002 | |
| M513 | 3.5–3.8 μM | 0.8–0.9 μM | RCK1 | 70–80 | Bao et al., 2002 | |
| D362/D367 | 17.2 ± 4.0 μM | 4.6 ± 1.0 μM | RCK1 | 60–80 | Xia et al., 2002 | |
| D81 | S0–S1 | 10–30 | Braun and Sy, 2001 | |||
| Low affinity | Ca2+/Mg2+ | RCK1 | ∼60 | |||
| E374/E399 | Mg2+ | 60–70 | Shi et al., 2002 | |||
| Ca2+ | 4.1 ± 3.5 mM | 1.8 ± 1.2 mM | 50–70 | Xia et al., 2002 | ||
| 2.3–3.1 mM | 0.5–0.9 mM | 50–70 | Zhang et al., 2001 | |||
| Mg2+ | 9–22 mM | 2–6 mM | 70 | Zhang et al., 2001 | ||
| 15 mM | 3.6 mM | 75 | Shi and Cui, 2001 | |||
| High affinity | Ca2+ | |||||
| Δ896–903 + M513I | ∼125 | Bao et al., 2002 | ||||
| D(897–901)N + D362A/D367A | ∼140 | Xia et al., 2002 | ||||
| D895N + D81N | ∼80 | Braun and Sy, 2001 |
V equivalent is the shift required in the voltage to maintain the same Po of 0.5 after the indicated mutations in the presence of 10–100 μM Ca2+i for the high affinity sites and 10 mM Ca2+i or Mg2+i for the low affinity sites.
All sequence numbers are adjusted to the sequence with EMBL/GenBank/DDBJ accession no. L16912 (Butler et al., 1993) from Nucleotide in PubMed with the numbering starting at the second M (MDALI). The mutations that identify each site and identifying sequence are: The Ca2+ bowl is defined by Sequence I in the text. Various mutations in this region that greatly reduce Ca2+ sensitivity typically include one or more of the five consecutive aspartates (D897–901), such as D(897–901)N or D897–898 deleted, or the D895N which changes the D two residues before the string of aspartates. M513I identified by MRSFIK. D362A/D367A identified by DFLHKD. D81N identified by DEKEE. E399A identified by EFYQG.
