ABCC7 p.Thr421Ala

[switch to full view]
Comments [show]
Publications
PMID: 17381427 [PubMed] Pereira MM et al: "Activation mechanisms for the cystic fibrosis transmembrane conductance regulator protein involve direct binding of cAMP."
No. Sentence Comment
7 Introduction of a mutation (T421A) in a motif predicted to be important for cyclic nucleotide binding decreased the higher affinity binding of cAMP to 9.2 µM.
X
ABCC7 p.Thr421Ala 17381427:7:28
status: NEW
Login to comment

39 The T421A mutation was introduced into the pRSETB vector using Stratagene`s QuikChange® II Site-directed Mutagenesis kit and oligonucleotide primers (forward and reverse) containing the mutation amidst a 21 base-pair 5 - and 3 - flanking region.
X
ABCC7 p.Thr421Ala 17381427:39:4
status: NEW
Login to comment

154 However, as for ATP binding, cAMP displacement followed a biexponential curve, yielding values for half-maximal displacement of [3 H]cAMP of 2.6 and 167 µM. Sullivan et al. [18] compared the whole-cell chloride channel activity elicited by injection of 50 µM cAMP into cells expressing wild-type CFTR or the mutant form, T421A.
X
ABCC7 p.Thr421Ala 17381427:154:331
status: NEW
Login to comment

157 We introduced the T421A mutation into CFTR cDNA (see the Experimental section) and expressed an NBD1-R domain protein to investigate the effect on cAMP binding.
X
ABCC7 p.Thr421Ala 17381427:157:18
status: NEW
Login to comment

158 As shown in Figure 5(B), the T421A mutant protein bound [3 H]cAMP but showed half-maximal displacement by unlabelled cAMP at 9.2 and 201 µM.
X
ABCC7 p.Thr421Ala 17381427:158:29
status: NEW
Login to comment

159 Thus the results suggest that the T421A mutation results in decreased affinity of the higher affinity binding, which is responsible for activation of CFTR.
X
ABCC7 p.Thr421Ala 17381427:159:34
status: NEW
Login to comment

177 All the results are means + - S.E.M.; (A) n = 7 for displacement by cAMP; (B) displacement by cAMP from wild-type (closed circles, n = 5) or T421A (open squares, n = 5) NBD1-R domain protein.
X
ABCC7 p.Thr421Ala 17381427:177:141
status: NEW
Login to comment

218 We synthesized a T421A mutant form of the NBD1-R domain protein and showed a decreased affinity for cAMP binding (Figure 5B), consistent with the demonstration that the full-length T421A CFTR showed reduced chloride channel activity in whole cells [18].
X
ABCC7 p.Thr421Ala 17381427:218:17
status: NEW
X
ABCC7 p.Thr421Ala 17381427:218:181
status: NEW
Login to comment

PMID: 8548288 [PubMed] Sullivan SK et al: "Identification and partial characterization of a domain in CFTR that may bind cyclic nucleotides directly."
No. Sentence Comment
125 The current was only 18 + 13 % (n = 3) of wild-type level for the mutant channel with the glutamate at position 407 substituted by glutamine (mutant E407Q, using the single-letter amino-acid code); 16 + 3 % (n = 4) for the L408A mutant; and 17 ±+1 % (n = 4) for the T421A mutant (data not shown).
X
ABCC7 p.Thr421Ala 8548288:125:271
status: NEW
Login to comment

124 The current was only 18 + 13 % (n = 3) of wild-type level for the mutant channel with the glutamate at position 407 substituted by glutamine (mutant E407Q, using the single-letter amino-acid code); 16 + 3 % (n = 4) for the L408A mutant; and 17 &#b1;+1 % (n = 4) for the T421A mutant (data not shown).
X
ABCC7 p.Thr421Ala 8548288:124:270
status: NEW
Login to comment