Multiple C-terminal motifs of the 46-kDa mannose 6-phosphate receptor tail contribute to efficient binding of medium chains of AP-2 and AP-3.
J Biol Chem
; 276(6): 4298-303, 2001 Feb 09.
Article
em En
| MEDLINE
| ID: mdl-11071885
ABSTRACT
The interaction of adaptor protein (AP) complexes with signal structures in the cytoplasmic domains of membrane proteins is required for intracellular sorting. Tyrosine- or dileucine-based motifs have been reported to bind to medium chain subunits (mu) of AP-1, AP-2, or AP-3. In the present study, we have examined the interaction of the entire 67-amino acid cytoplasmic domain of the 46-kDa mannose 6-phosphate receptor (MPR46-CT) containing tyrosine- as well as dileucine-based motifs with mu2 and mu3A chains using the yeast two-hybrid system. Both mu2 and mu3A bind specifically to the MPR46-CT. In contrast, mu3A fails to bind to the cytoplasmic domain of the 300-kDa mannose 6-phosphate receptor. Mutational analysis of the MPR46-CT revealed that the tyrosine-based motif and distal sequences rich in acidic amino acid residues are sufficient for effective binding to mu2. However, the dileucine motif was found to be one part of a consecutive complex C-terminal structure comprising tyrosine and dileucine motifs as well as clusters of acidic residues necessary for efficient binding of mu3A. Alanine substitution of 2 or 4 acidic amino acid residues of this cluster reduces the binding to mu3A much more than to mu2. The data suggest that the MPR46 is capable of interacting with different AP complexes using multiple partially overlapping sorting signals, which might depend on posttranslational modifications or subcellular localization of the receptor.
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Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Fatores de Transcrição
/
Receptor IGF Tipo 2
/
Complexo 1 de Proteínas Adaptadoras
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Complexo 2 de Proteínas Adaptadoras
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Complexo 3 de Proteínas Adaptadoras
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Subunidades mu do Complexo de Proteínas Adaptadoras
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Proteínas Monoméricas de Montagem de Clatrina
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Proteínas de Ligação a DNA
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Proteínas de Membrana
Idioma:
En
Revista:
J Biol Chem
Ano de publicação:
2001
Tipo de documento:
Article
País de afiliação:
Alemanha