The 46 kDa mannose-6-phosphate receptor contains a signal for basolateral sorting within the 19 juxtamembrane cytosolic residues.
The cytosolic domain of the 46 kDa mannose-6-phosphate receptor (MPR 46) contains a signal that mediates sorting of the receptor and of a reporter protein to the basolateral surface domain of Madin-Darby canine kidney cells. Progressive truncation of the 67 cytosolic residues indicated that the 19 juxtamembrane residues are sufficient for basolateral sorting. Alanine/glycine-scanning mutagenesis identified Glu-11 and Ala-17 as the critical residues between residues 7 and 19. Glu-11 is also of critical importance for the one of the three internalization signals in the cytosolic tail of the receptor [Denzer, Weber, Hille-Rehfeld, von Figura and Pohlmann (1997) Biochem. J. 326, 497-505]. Although overlapping, the signals for basolateral sorting and internalization depend on different residues. The basolateral sorting signal of MPR 46 is distinct from tyrosine- or dileucine-based basolateral sorting signals and also lacks similarity to the few other basolateral signals that do not fall into these two classes.
Bresciani
R
R
Biochemie II, Universität Göttingen, Gosslerstrasse 12D, D-37073 Göttingen, Federal Republic of Germany.
Denzer
K
K
Pohlmann
R
R
von Figura
K
K
D000409:Alanine / Q000235:genetics / Q000502:physiology; D000595:Amino Acid Sequence; D000818:Animals; D002460:Cell Line; D003600:Cytosol / Q000378:metabolism*; D004285:Dogs; D019084:Fluorescent Antibody Technique, Indirect; D018698:Glutamic Acid / Q000235:genetics / Q000502:physiology; D006801:Humans; D007425:Intracellular Membranes / Q000378:metabolism; D007668:Kidney / Q000166:cytology; D008969:Molecular Sequence Data; D008970:Molecular Weight; D016297:Mutagenesis, Site-Directed; D011233:Precipitin Tests; D017527:Receptor, IGF Type 2 / Q000096:biosynthesis* / Q000235:genetics / Q000502:physiology / Q000648:ultrastructure; D011994:Recombinant Proteins / Q000096:biosynthesis / Q000235:genetics / Q000648:ultrastructure; D017384:Sequence Deletion; D014162:Transfection
D017527:Receptor, IGF Type 2; D011994:Recombinant Proteins; D018698:Glutamic Acid; D000409:Alanine