The Acidic Cluster of the CK2 Site of the Cation-dependent Mannose 6-Phosphate Receptor (CD-MPR) but Not Its Phosphorylation Is Required for GGA1 and AP-1 Binding
| Autor: | Jack Rohrer, Stefan Höning, Jacqueline Stöckli |
|---|---|
| Rok vydání: | 2004 |
| Předmět: |
Endosome
Molecular Sequence Data Mannose Biology Biochemistry Receptor IGF Type 2 Mice 03 medical and health sciences chemistry.chemical_compound L Cells 0302 clinical medicine GGA1 Animals Amino Acid Sequence Phosphorylation Receptor Molecular Biology 030304 developmental biology 0303 health sciences 572: Biochemie ADP-Ribosylation Factors Signal transducing adaptor protein Cell Biology Cell biology Transcription Factor AP-1 Adaptor Proteins Vesicular Transport chemistry Mutation Casein kinase 2 Carrier Proteins Sequence Alignment 030217 neurology & neurosurgery Cation-dependent mannose-6-phosphate receptor |
| Zdroj: | Journal of Biological Chemistry. 279:23542-23549 |
| ISSN: | 0021-9258 |
| DOI: | 10.1074/jbc.m313525200 |
| Popis: | Lysosomal biogenesis depends on proper transport of lysosomal enzymes by the cation-dependent mannose 6-phosphate receptor (CD-MPR) from the trans-Golgi network (TGN) to endosomes. Trafficking of the CDMPR is mediated by sorting signals in its cytoplasmic tail. GGA1 (Golgi-localizing, gamma-ear-containing, ARF-binding protein-1) binds to CD-MPR in the TGN and targets the receptor to clathrin-coated pits for transport from the TGN to endosomes. The motif of the CD-MPR that interacts with GGA1 was shown to be 61DXXLL65. Reports on increased affinity of cargo, when phosphorylated by casein kinase 2 (CK2), to GGAs focused our interest on the effect of the CD-MPR CK2 site on binding to GGA1. Here we demonstrate that Glu58 and Glu59 of the CK2 site are essential for high affinity GGA1 binding in vitro, whereas the phosphorylation of Ser57 of the CD-MPR has no influence on receptor binding to GGA1. Furthermore, the in vivo interaction between GGA1 and CD-MPR was abolished only when all residues involved in GGA1 binding were mutated, namely, Glu58, Glu59, Asp61, Leu64, and Leu65. In contrast, the binding of adaptor protein-1 (AP-1) to CD-MPR required all the glutamates surrounding the phosphorylation site, namely, Glu55, Glu56, Glu58, and Glu59, but like GGA1 binding, was independent of the phosphorylation of Ser57. The binding affinity of GGA1 to the CD-MPR was found to be 2.4-fold higher than that of AP-1. This could regulate the binding of the two proteins to the partly overlapping sorting signals, allowing AP-1 binding to the CD-MPR only when GGA1 is released upon autoinhibition by phosphorylation. |
| Databáze: | OpenAIRE |
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