Publication Date:
1990-05-11
Description:
The endosomal compartment of polarized epithelial cells is a major crossroads for membrane traffic. Proteins entering this compartment from the cell surface are sorted for transport to one of several destinations: recycling to the original cell surface, targeting to lysosomes for degradation, or transcytosis to the opposite surface. The polymeric immunoglobulin receptor (pIgR), which is normally transcytosed from the basolateral to the apical surface, was used as a model to dissect the signals that mediate this sorting event. When exogenous receptor was expressed in Madin-Darby Canine Kidney (MDCK) cells, it was shown that phosphorylation of pIgR at the serine residue at position 664 is required for efficient transcytosis. Replacement of this serine with alanine generated a receptor that is transcytosed only slowly, and appears to be recycled. Conversely, substitution with aspartic acid (which mimics the negative charge of the phosphate group) results in rapid transcytosis. It was concluded that phosphorylation is the signal that directs the pIgR from the endosome into the transcytotic pathway.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Casanova, J E -- Breitfeld, P P -- Ross, S A -- Mostov, K E -- R01-AI-25144/AI/NIAID NIH HHS/ -- New York, N.Y. -- Science. 1990 May 11;248(4956):742-5.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Department of Anatomy, University of California, San Francisco 94143.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/2110383" target="_blank"〉PubMed〈/a〉
Keywords:
Alanine
;
Animals
;
Aspartic Acid
;
Cell Line
;
Cell Membrane/immunology/metabolism
;
Endocytosis
;
Immunoglobulin A/metabolism
;
Kinetics
;
Ligands
;
Membrane Glycoproteins/metabolism
;
Molecular Weight
;
Mutation
;
Phosphorylation
;
Rats
;
Receptors, Immunologic
;
Secretory Component/genetics/*metabolism
;
Serine
Print ISSN:
0036-8075
Electronic ISSN:
1095-9203
Topics:
Biology
,
Chemistry and Pharmacology
,
Computer Science
,
Medicine
,
Natural Sciences in General
,
Physics
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