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Polarized sorting of the polymeric immunoglobulin receptor in the exocytotic and endocytotic pathways is controlled by the same amino acids.
Author(s) -
Aroeti B.,
Mostov K.E.
Publication year - 1994
Publication title -
the embo journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 7.484
H-Index - 392
eISSN - 1460-2075
pISSN - 0261-4189
DOI - 10.1002/j.1460-2075.1994.tb06513.x
Subject(s) - transcytosis , polymeric immunoglobulin receptor , endocytosis , biology , microbiology and biotechnology , cytoplasm , receptor , golgi apparatus , protein targeting , brush border , apical membrane , transport protein , membrane protein , biochemistry , membrane , endoplasmic reticulum , vesicle
Polarized epithelial cells can sort plasma membrane proteins to the apical or basolateral domain either by direct targeting from the trans‐Golgi network (TGN) or by targeting to one surface, followed by endocytosis and transcytosis to the opposite surface. In Madin‐Darby canine kidney (MDCK) cells, targeting of the polymeric immunoglobulin receptor (pIgR) to the basolateral surface is controlled by a sorting signal residing in the membrane proximal 17 amino acids of the cytoplasmic domain of this receptor. We have recently found that individual mutations at any of three residues in this signal, His656, Arg657 and Val660, substantially decrease targeting from the TGN to the basolateral surface and correspondingly increase targeting from the TGN to the apical surface. Here we report that these mutations decrease the recycling of basolaterally endocytosed pIgR to that surface, and correspondingly increase its transcytosis to the apical surface. This effect occurred in mutant pIgRs that either contained the full‐length cytoplasmic domain or were truncated to contain only the 17‐residue basolateral targeting signal, and was independent of phosphorylation of pIgR at Ser664. Our results indicate that polarized sorting of the pIgR in the endocytotic and exocytotic pathways are controlled by the same amino acids.