Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
28
pubmed:dateCreated
1993-11-24
pubmed:abstractText
The major subunit of the human asialoglycoprotein receptor contains signals for efficient endocytosis and specific basolateral expression in polarized Madin-Darby canine kidney cells, both of which are located within its 40-residue cytoplasmic domain. The aromatic residue in this segment, tyrosine 5, which is necessary for efficient clustering into clathrin-coated pits at the plasma membrane, is also necessary for exclusive basolateral delivery. Mutation of this residue to alanine resulted in a nonpolar expression of the protein. Replacement of tyrosine 5 with phenylalanine yielded almost wild-type rates of endocytosis as well as specific basolateral expression, indicating that tyrosine phosphorylation is not essential for either sorting step. The close similarity between the two sorting signals was further corroborated by deletion mutants showing that the amino-terminal 10 residues of the cytoplasmic domain are sufficient for basolateral polarity and efficient endocytosis. The kinetics of appearance of newly synthesized wild-type and mutant receptor protein at the apical and basolateral surfaces indicate that these proteins are sorted intracellularly and are transported directly to the respective domains. Mutants affected in basolateral sorting lost polarity, i.e, appeared to similar extents on both surfaces, indicating that there is no significant apical sorting information elsewhere in the protein. The close correlation between endocytosis and basolateral polarity suggests common recognition mechanisms at the plasma membrane and in the trans-Golgi network.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Oct
pubmed:issn
0021-9258
pubmed:author
pubmed:issnType
Print
pubmed:day
5
pubmed:volume
268
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
20772-7
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed-meshheading:8407903-3T3 Cells, pubmed-meshheading:8407903-Alanine, pubmed-meshheading:8407903-Amino Acid Sequence, pubmed-meshheading:8407903-Animals, pubmed-meshheading:8407903-Asialoglycoprotein Receptor, pubmed-meshheading:8407903-Asialoglycoproteins, pubmed-meshheading:8407903-Base Sequence, pubmed-meshheading:8407903-Cells, Cultured, pubmed-meshheading:8407903-Cytoplasm, pubmed-meshheading:8407903-Dogs, pubmed-meshheading:8407903-Endocytosis, pubmed-meshheading:8407903-Humans, pubmed-meshheading:8407903-Kinetics, pubmed-meshheading:8407903-Membrane Potentials, pubmed-meshheading:8407903-Mice, pubmed-meshheading:8407903-Molecular Sequence Data, pubmed-meshheading:8407903-Oligodeoxyribonucleotides, pubmed-meshheading:8407903-Point Mutation, pubmed-meshheading:8407903-Receptors, Cell Surface, pubmed-meshheading:8407903-Sequence Deletion, pubmed-meshheading:8407903-Transfection, pubmed-meshheading:8407903-Tyrosine
pubmed:year
1993
pubmed:articleTitle
Related signals for endocytosis and basolateral sorting of the asialoglycoprotein receptor.
pubmed:affiliation
Department of Biochemistry, University of Basel, Switzerland.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't