ABCMdb

PMID: 11073882

Matsuoka T, Matsushita K, Katayama Y, Fujita A, Inageda K, Tanemoto M, Inanobe A, Yamashita S, Matsuzawa Y, Kurachi Y
C-terminal tails of sulfonylurea receptors control ADP-induced activation and diazoxide modulation of ATP-sensitive K(+) channels.
Circ Res. 2000 Nov 10;87(10):873-80., [PubMed]

Sentences

No. Mutations Sentence Comment

96 ABCC8 p.Lys1384Ala Effects of Mutations in NBD2 of SUR2B and SUR1 on the ADP and Diazoxide Action Like other ATP-binding cassette proteins, SURs possess 2 nucleotide-binding domains (NBD1 and NBD2, respectively).3 It was shown that SUR1 binds ATP at NBD1 and ADP at NBD2.24 The NBDs possess the Walker A and B motifs to form a portion of a nucleotide-binding pocket.25 In various ATP-binding proteins, Walker A motif in NBDs is responsible for binding or hydrolysis of nucleotides, where the highly conserved lysine residue plays a critical role.26-28 The mutation of this lysine residue in NBD2 extinguishes the ADP-mediated activation of SUR1 and SUR2A-KATP channels.19,21,29 Therefore, we introduced mutations of the lysine residue in NBD2 of SUR2B and SUR1 (K1348M in SUR2B and K1384A in SUR1) and examined the effects of ADP and diazoxide on the mutant SUR/ Kir6.2 channels (Figure 3). Login to comment 97 ABCC8 p.Lys1384Ala Effects of Mutations in NBD2 of SUR2B and SUR1 on the ADP and Diazoxide Action Like other ATP-binding cassette proteins, SURs possess 2 nucleotide-binding domains (NBD1 and NBD2, respectively).3 It was shown that SUR1 binds ATP at NBD1 and ADP at NBD2.24 The NBDs possess the Walker A and B motifs to form a portion of a nucleotide-binding pocket.25 In various ATP-binding proteins, Walker A motif in NBDs is responsible for binding or hydrolysis of nucleotides, where the highly conserved lysine residue plays a critical role.26-28 The mutation of this lysine residue in NBD2 extinguishes the ADP-mediated activation of SUR1 and SUR2A-KATP channels.19,21,29 Therefore, we introduced mutations of the lysine residue in NBD2 of SUR2B and SUR1 (K1348M in SUR2B and K1384A in SUR1) and examined the effects of ADP and diazoxide on the mutant SUR/ Kir6.2 channels (Figure 3). Login to comment 100 ABCC8 p.Lys1384Ala The mutant SUR1(K1384A)/Kir6.2 channel also scarcely responded to ADP (Figure 3B). Login to comment 101 ABCC8 p.Lys1384Ala ABCC8 p.Lys1384Ala The mutant SUR1(K1384A)/Kir6.2 channel also scarcely responded to ADP (Figure 3B). Login to comment 102 ABCC8 p.Lys1384Ala Different from the SUR2B mutant, diazoxide (30 and 300 òe;mol/L) enhanced the SUR1(K1384A)/ Kir6.2 channel to b07;0.1 and b07;0.2 in rNPo, respectively, irrespective of [ADP]. Login to comment 104 ABCC8 p.Lys1384Ala ABCC8 p.Lys1384Ala Effects of intracellular ADP, diazoxide, and pinacidil on SUR2B(K1348M)/ Kir6.2 (A) and SUR1(K1384A)/Kir6.2 (B) channels. Left, Effects of ADP and diazoxide (DZX) or pinacidil (PIN) on SUR2(K1348M)/Kir6.2 and SUR1(K1384A)/ Kir6.2 channels. ATP, ADP, and diazoxide were added to the bath solution as indicated by bars. Right, Relationship between the concentration of ADP and relative NPo (rNPo) in the absence (Ǧc;) and presence of diazoxide (U, 30 òe;mol/L and ጗, 300 òe;mol/L) or pinacidil (Ⴢ, 100 òe;mol/L). Login to comment 105 ABCC8 p.Lys1384Ala ABCC8 p.Lys1384Ala Effects of intracellular ADP, diazoxide, and pinacidil on SUR2B(K1348M)/ Kir6.2 (A) and SUR1(K1384A)/Kir6.2 (B) channels. Left, Effects of ADP and diazoxide (DZX) or pinacidil (PIN) on SUR2(K1348M)/Kir6.2 and SUR1(K1384A)/ Kir6.2 channels. ATP, ADP, and diazoxide were added to the bath solution as indicated by bars. Right, Relationship between the concentration of ADP and relative NPo (rNPo) in the absence (Ǧc;) and presence of diazoxide (U, 30 òe;mol/L and ጗, 300 òe;mol/L) or pinacidil (Ⴢ, 100 òe;mol/L). Login to comment 106 ABCC8 p.Lys1384Ala Effects of Mutations in NBD2 of SUR2B and SUR1 on the ADP and Diazoxide Action Like other ATP-binding cassette proteins, SURs possess 2 nucleotide-binding domains (NBD1 and NBD2, respectively).3 It was shown that SUR1 binds ATP at NBD1 and ADP at NBD2.24 The NBDs possess the Walker A and B motifs to form a portion of a nucleotide-binding pocket.25 In various ATP-binding proteins, Walker A motif in NBDs is responsible for binding or hydrolysis of nucleotides, where the highly conserved lysine residue plays a critical role.26-28 The mutation of this lysine residue in NBD2 extinguishes the ADP-mediated activation of SUR1 and SUR2A-KATP channels.19,21,29 Therefore, we introduced mutations of the lysine residue in NBD2 of SUR2B and SUR1 (K1348M in SUR2B and K1384A in SUR1) and examined the effects of ADP and diazoxide on the mutant SUR/ Kir6.2 channels (Figure 3). Login to comment 110 ABCC8 p.Lys1384Ala The mutant SUR1(K1384A)/Kir6.2 channel also scarcely responded to ADP (Figure 3B). Login to comment 111 ABCC8 p.Lys1384Ala Different from the SUR2B mutant, diazoxide (30 and 300 ␮mol/L) enhanced the SUR1(K1384A)/ Kir6.2 channel to Ϸ0.1 and Ϸ0.2 in rNPo, respectively, irrespective of [ADP]. Login to comment 114 ABCC8 p.Lys1384Ala ABCC8 p.Lys1384Ala Effects of intracellular ADP, diazoxide, and pinacidil on SUR2B(K1348M)/ Kir6.2 (A) and SUR1(K1384A)/Kir6.2 (B) channels. Left, Effects of ADP and diazoxide (DZX) or pinacidil (PIN) on SUR2(K1348M)/Kir6.2 and SUR1(K1384A)/ Kir6.2 channels. ATP, ADP, and diazoxide were added to the bath solution as indicated by bars. Right, Relationship between the concentration of ADP and relative NPo (rNPo) in the absence (⅜) and presence of diazoxide (U, 30 ␮mol/L and ⅷ, 300 ␮mol/L) or pinacidil (ᮀ, 100 ␮mol/L). Login to comment 125 ABCC8 p.Lys1384Ala In the chimera SUR1-2A/Kir6.2 and the mutant SUR1(K1384A)/Kir6.2 channels, the ADP-dependent component was largely attenuated, and diazoxide (300 òe;mol/L) increased the channel rNPo by b07;0.2 irrespective of [ADP]. Login to comment 126 ABCC8 p.Lys1384Ala In the chimera SUR1-2A/Kir6.2 and the mutant SUR1(K1384A)/Kir6.2 channels, the ADP-dependent component was largely attenuated, and diazoxide (300 òe;mol/L) increased the channel rNPo by b07;0.2 irrespective of [ADP]. Login to comment 135 ABCC8 p.Lys1384Ala In the chimera SUR1-2A/Kir6.2 and the mutant SUR1(K1384A)/Kir6.2 channels, the ADP-dependent component was largely attenuated, and diazoxide (300 ␮mol/L) increased the channel rNPo by Ϸ0.2 irrespective of [ADP]. Login to comment