ABCC1 p.Arg1202Asp
[switch to full view]Comments [show]
None has been submitted yet.
PMID: 15208328
[PubMed]
Situ D et al: "Mutational analysis of ionizable residues proximal to the cytoplasmic interface of membrane spanning domain 3 of the multidrug resistance protein, MRP1 (ABCC1): glutamate 1204 is important for both the expression and catalytic activity of the transporter."
No.
Sentence
Comment
108
In contrast, expression levels of the R1202D and E1204K mutants were substantially reduced (by Ͼ75%).
X
ABCC1 p.Arg1202Asp 15208328:108:38
status: NEW109 A Northern blot analysis performed on total RNA isolated from the transfected cells indicated that the R1202D and E1204K mRNA levels were comparable with wild-type MRP1 mRNA levels, thus excluding the possibility that the low R1202D and E1204K protein levels could be caused by differences in transfection efficiency (results not shown).
X
ABCC1 p.Arg1202Asp 15208328:109:103
status: NEWX
ABCC1 p.Arg1202Asp 15208328:109:226
status: NEW113 Membrane vesicles prepared from HEK293T cells transfected with empty vector [pcDNA3.1] and vector containing the wild-type (WT-MRP1) and mutant (R1197E, R1202D, E1204K, and R1249D) cDNAs were immunoblotted with mAb QCRL-1. Shown is a representative immunoblot of membrane vesicles (1 and 2 g of protein) from a single transfection.
X
ABCC1 p.Arg1202Asp 15208328:113:153
status: NEW141 Transport Activities of TM16/17 Arg1197 and Arg1249 Mutants-Unlike the R1202D and E1204K mutants, oppositely charged substitutions of Arg1197 (R1197E) and Arg1249 (R1249D) did not adversely affect expression of MRP1 (Fig. 3A).
X
ABCC1 p.Arg1202Asp 15208328:141:71
status: NEW189 This idea is supported by the observation that membrane expression of the R1202D and E1204K mutants in mammalian cells can be substantially increased when transfected cells are grown at lower temperatures (30 °C) where the stringency of the proofreading machinery for monitoring protein folding is diminished.2 Because neutral (Leu, Gly) substitutions of TM16 Arg1202 and Glu1204 did not affect MRP1 expression in any significant way, it may be concluded that it is the opposite charge of the side chains of the substituting amino acids in the nonexpress- 2 A. Haimeur, R. G. Deeley, and S. P. C. Cole, unpublished observations.
X
ABCC1 p.Arg1202Asp 15208328:189:74
status: NEW199 ing R1202D and E1204K mutants that is key to MRP1 protein destabilization.
X
ABCC1 p.Arg1202Asp 15208328:199:4
status: NEW200 In this regard, it is worth noting that replacing Arg1202 with an Asp (or Glu1204 with a Lys) results in a potential net gain of two charges in the cytoplasmic half of TM16 as well as placing two same-charge ionizable residues in relatively close proximity to one another which could well perturb the ␣-helical geometry of TM16 and contribute to misfolding or aberrant TM helix-packing.
X
ABCC1 p.Arg1202Asp 15208328:200:50
status: NEW