ABCMdb

ABCB1 p.Ala935Cys

None has been submitted yet.

Publications

PMID: 10681495 [PubMed] Loo TW et al: "The packing of the transmembrane segments of human multidrug resistance P-glycoprotein is revealed by disulfide cross-linking analysis."

No. Sentence Comment

77 In these cross-linking experiments, the amount of oxidant was lowered by 10-fold (0.2 mM), and the minimum temperature required to induce cross-TABLE I Cross-linking analysis of P-gp Cross-linking of S993C (TM12) with residues in the following TM: TM1 TM2 TM3 TM4 TM5 M51C -a Y130C - G185C - G226C - I293C - V52C - I131C - I186C - L227C ϩb T294C - V53C - Q132C - G187C - S228C - A295C ϩ G54C - V133C - D188C - A229C - N296C - T55C - S134C - K189C - A230C - I297C - L56C - F135C - I190C - V231C ϩ S298C - A57C - W136C - G191C - W232C ϩ I299C ϩ A58C - C137C - M192C - A233C ϩ G300C - I59C - L138C - F193C - K234C - A301C - I60C - A139C - F194C - I235C ϩ A302C - H61C - A140C - Q195C - L236C ϩ F303C - G141C - S196C - S237C - L304C - Cross-linking of P350C (TM6) with residues in the following TM: TM7 TM8 TM9 TM10 TM11 F711C - F770C - A828C - I867C - A935C - V712C - F771C - I829C - I868C - H936C - V713C - L772C - G830C - A869C - I937C - G714C - Q773C - S831C - I870C - F938C - V715C - G774C - R832C - A871C - G939C ϩ F716C - F775C - L833C - G872C - I940C - C717C - T776C - A834C - V873C - T941C - A718C - F777C - V835C - V874C ϩ F942C - I719C - G778C - I836C - E875C ϩ S943C - I720C - K779C - T837C - M876C ϩ F944C - N721C - A780C - Q838C - K877C - T945C - G722C - G781C - N839C - M878C - Q946C - G723C - E782C - I840C - L879C - A947C - I783C - a -, no cross-linked product detected in SDS-PAGE. b ϩ, cross-linked product detected in SDS-PAGE. Login to comment

PMID: 12609990 [PubMed] Loo TW et al: "Substrate-induced conformational changes in the transmembrane segments of human P-glycoprotein. Direct evidence for the substrate-induced fit mechanism for drug binding."

No. Sentence Comment

107 Accordingly, we tested whether the drug substrates colchicine, demecolcine, progesterone, cis-(Z)-flupenthixol, verapamil, or vinblastine stimulated the ATPase activities of histidine-tagged mutants P350C(TM6)/A935C- (TM11), P350C(TM6)/G939C(TM11), and P350C(TM6)/V991C- (TM12). Login to comment
124 In the presence of drug substrate (progesterone), TM segments 11 and 12 undergo rotational and/or lateral movements so that cross-linking can occur between P350C and V991C (black ball) in TM12 and with A935C (red ball) and G939C (turquoise ball) in TM11. Login to comment
135 The presence of progesterone, however, promoted cross-linking of residue P350C(TM6) with two residues in TM 11 (A935C and G939C) and to residue V991C in TM12. Login to comment
145 It is possible that cyclosporin A altered the tilt or distance between TM6 and TM11 such that only A939C but not A935C were close enough to P350C to be cross-linked. Login to comment

PMID: 14749322 [PubMed] Loo TW et al: "Val133 and Cys137 in transmembrane segment 2 are close to Arg935 and Gly939 in transmembrane segment 11 of human P-glycoprotein."

No. Sentence Comment

7 Two of the 110 TM2/TM11 mutants, V133C(TM2)/G939C(TM11) and C137C(TM2)/A935C (TM11), were cross-linked at 4 °C, when thermal motion is reduced. Login to comment
100 When cross-linking was carried out at 22 °C, only mutants V133C(TM2)/G939C(TM11), C137C(TM2)/A935C (TM11), and L138C(TM2)/A935C(TM11) formed detectable cross-linked products. Login to comment
106 At 4 °C, time-dependent cross-linking was observed in mutants V133C(TM2)/G939C(TM11) and C137C(TM2)/A935C (TM11), but not in mutant L138C(TM2)/A935C(TM11) even after 32 min (Fig. 3). Login to comment
124 TABLE I Cross-linking between residues in TM2 and TM11 -, no cross-linked product detected on SDS-polyacrylamide gels at 37 °C; ϩ, relatively weak cross-linking (Ͻ50% of P-gp cross-linked) at 37 °C; ϩϩ, relatively strong cross-linking (Ͼ50% of P-gp cross-linked) at 37 °C; *, cross-linked product also detected at 22 °C; **, cross-linked product also detected at 22 and 4 °C. TM2 TM11 A935C H936C I937C F938C G939C I940C T941C F942C S943C F944C A128C - - - - - - - - - - A129C - - - - - - - - - - Y130C - - - - ϩ ϩ - ϩ ϩ - I131C - - - - - - - - - - Q132C - - - - - - - - - - V133C - - - ϩ ϩϩ, ** - - ϩ ϩ - S134C ϩ ϩ - - ϩ ϩ - - - - F135C - - - - - - - - - - W136C - - - - - - - - - - C137C ϩϩ, ** - - - ϩ - - - - - L138C ϩϩ, * - - - - - - - - - TM11 are close to each other at their cytoplasmic ends. Login to comment

PMID: 15509712 [PubMed] Pleban K et al: "P-glycoprotein substrate binding domains are located at the transmembrane domain/transmembrane domain interfaces: a combined photoaffinity labeling-protein homology modeling approach."

No. Sentence Comment

255 With respect to putative TMs 2 and 11, cross-links were found for the double-cysteine mutants Val133/Gly939, C137C/A935C, and L138C/ A935C. Login to comment

PMID: 22700974 [PubMed] Loo TW et al: "The ATPase activity of the P-glycoprotein drug pump is highly activated when the N-terminal and central regions of the nucleotide-binding domains are linked closely together."

No. Sentence Comment

106 The location of residues that were mutated to cysteine to test for the effect of cross-linking between NBD1 and NBD2 (P517C/I1050C), NBD1 and TMD2 (L443C/S909C), ICL1 and ICL3 (D177C/N820C), TM segments 2 and 11 (C137/A935C) or 6 and 12 (T333C/L975C) are shown. Login to comment
150 We tested the effects of M4M and M17M cross-linking on the ATPase activity of mutant L175C/N820C and found that the effects were similar to those observed with mutant D177C/ N820C (Fig. 3C). Login to comment
154 ATPase Activity Is Not Activated when the Homologous Halves Are Cross-linked at Locations Predicted Not to Undergo Large Distance Changes during the Open to Closed Conformational Change-Mutant C137/A935C contains natural Cys-137 in TM segment 2 (TMD1) and the A935C mutation in TM segment 11 (TMD2). Login to comment
158 In previous studies we showed that mutants C137/A935C (39) and L443C/ S909C (27) had verapamil-stimulated ATPase activities similar to Cys-less P-gp. Login to comment
159 Membranes prepared from cells expressing mutants C137/ A935C or L443C/S909C were treated with M4M cross-linker. Login to comment
163 These results indicate that stimulation of ATPase activity observed in M4M cross-linked mutants P517C/I1050C (Fig. 2B), D177C/N820C, or L175C/N820C (Fig. 3C) was likely a specific effect of trapping the protein in the closed conformation. Login to comment
166 A, membranes prepared from HEK 293 cells expressing the NBD1/TMD2 mutant L443C/ S909C or the TM2/TM11 mutant C137/A935C were treated with (ϩ) or without (-) the M4M cross-linker. Login to comment
168 The positions of the cross-linked (X-link) and mature (170 kDa) P-gps are indicated. B, membranes expressing mutants L443C/ S909C or C137/A935C were treated with or without (None) M4M cross-linker and histidine-tagged P-gp isolated by nickel-chelate chromatography. Login to comment
282 The requirement for rotation or motion of the TM segments during the catalytic cycle may explain why direct cross-linking of the cysteines in mutant C137/A935C (TM2/TM11) (39) inhibited activity whereas cross-linking with M4M did not (this study). Login to comment
287 One explanation is that some movement is required at the C137/A935C and L443C/S909C interfaces during the catalytic cycle. Login to comment
301 Direct cross-linking of cysteines in the mutants would trap C137/A935C or L443C/S909C at a distance of about 5.6 Å, the average distance between ␣ carbons in a disulfide bond (64). Login to comment
304 Another plausible explanation as to why direct cross-linking of mutants C137/A935C or L443C/S909C inhibited activity is that cross-linking may have trapped the protein in an inactive conformation with the sites closer than normal. Login to comment
104 The location of residues that were mutated to cysteine to test for the effect of cross-linking between NBD1 and NBD2 (P517C/I1050C), NBD1 and TMD2 (L443C/S909C), ICL1 and ICL3 (D177C/N820C), TM segments 2 and 11 (C137/A935C) or 6 and 12 (T333C/L975C) are shown. Login to comment
161 A, membranes prepared from HEK 293 cells expressing the NBD1/TMD2 mutant L443C/ S909C or the TM2/TM11 mutant C137/A935C were treated with (af9;) or without (afa;) the M4M cross-linker. Login to comment
275 The requirement for rotation or motion of the TM segments during the catalytic cycle may explain why direct cross-linking of the cysteines in mutant C137/A935C (TM2/TM11) (39) inhibited activity whereas cross-linking with M4M did not (this study). Login to comment
280 One explanation is that some movement is required at the C137/A935C and L443C/S909C interfaces during the catalytic cycle. Login to comment
294 Direct cross-linking of cysteines in the mutants would trap C137/A935C or L443C/S909C at a distance of about 5.6 &#c5;, the average distance between ॷ carbons in a disulfide bond (64). Login to comment
297 Another plausible explanation as to why direct cross-linking of mutants C137/A935C or L443C/S909C inhibited activity is that cross-linking may have trapped the protein in an inactive conformation with the sites closer than normal. Login to comment