ABCMdb

PMID: 24129190

Emi Y, Harada Y, Sakaguchi M
Involvement of a di-leucine motif in targeting of ABCC1 to the basolateral plasma membrane of polarized epithelial cells.
Biochem Biophys Res Commun. 2013 Nov 8;441(1):89-95. doi: 10.1016/j.bbrc.2013.10.013. Epub 2013 Oct 12., [PubMed]

Sentences

No. Mutations Sentence Comment

92 ABCC1 p.Leu300Ala ABCC1 p.Ile301Ala Two ABCC1-HA point mutants, L300A and I301A, displayed a mixed distribution pattern, indicating diminished basolateral targeting specificity. Login to comment 93 ABCC1 p.Leu300Ala ABCC1 p.Ile301Ala In addition to their usual localization to the basolateral membrane, significant proportions of the L300A and I301A mutants were found in the apical vacuoles of every polarized HepG2 cell. Login to comment 94 ABCC1 p.Leu300Ala ABCC1 p.Ile301Ala All other ABCC1 point mutants tested exhibited normal basolateral localization, which excludes the possibility that perturbed localization of the L300A and I301A mutants was caused by gross protein misfolding arising from a point mutation and inhibition of ABCC1 trafficking to the basolateral membrane. Login to comment 102 ABCC1 p.Leu300Ala The MCCs of the L300A mutant against APN and Na,K-ATPase were 0.59 &#b1; 0.06 and 0.62 &#b1; 0.08, respectively, indicating a mixed apical and basolateral localization pattern (Fig. 3B). Login to comment 103 ABCC1 p.Ile301Ala ABCC1 p.Ile301Ala Similarly, MCCs of the I301A mutant were 0.63 &#b1; 0.05 and 0.59 &#b1; 0.04, respectively, which also suggests a mixed localization of the I301A mutant (Fig. 3C). Login to comment 113 ABCC1 p.Leu300Ala ABCC1 p.Ile301Ala Representative merged immunofluorescence images of the transfected cells are shown. The positions of apical vacuoles formed between juxtaposed polarized cells are indicated by white arrowheads. Scale bar, 20 lm. Only two variants, L300A and I301A, exhibited a mixed localization pattern. Login to comment 114 ABCC1 p.Leu300Ala ABCC1 p.Ile301Ala Only two variants, L300A and I301A, exhibited a mixed localization pattern. Login to comment 119 ABCC1 p.Leu300Ala ABCC1 p.Ile301Ala The L300A and I301A mutants lost their basolateral-specific targeting and produced a mixed staining pattern at both the apical and basolateral sides (Fig. 4). Login to comment 120 ABCC1 p.Leu300Ala ABCC1 p.Ile301Ala The L300A and I301A mutants lost their basolateral-specific targeting and produced a mixed staining pattern at both the apical and basolateral sides (Fig. 4). Login to comment 128 ABCC1 p.Leu300Ala ABCC1 p.Ile301Ala HepG2 cells were transiently cotransfected with 0.5 lg of the wild-type (A), L300A (B), or I301A (C) ABCC1-HA expression plasmids, along with 0.5 lg of empty vector pCMV-HA. Login to comment 129 ABCC1 p.Leu300Ala ABCC1 p.Ile301Ala HepG2 cells were transiently cotransfected with 0.5 lg of the wild-type (A), L300A (B), or I301A (C) ABCC1-HA expression plasmids, along with 0.5 lg of empty vector pCMV-HA. Login to comment 150 ABCC1 p.Leu300Ala ABCC1 p.Ile301Ala Single merged panels of representative apical, lateral, and x-z sections are shown. The L300A and I301A mutants displayed a mixed localization to the apical and basolateral membranes. Login to comment 151 ABCC1 p.Leu300Ala ABCC1 p.Ile301Ala Single merged panels of representative apical, lateral, and x-z sections are shown. The L300A and I301A mutants displayed a mixed localization to the apical and basolateral membranes. Login to comment