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Intracellular trafficking of furin is modulated by the phosphorylation state of a casein kinase II site in its cytoplasmic tail.
- Source :
-
The EMBO journal [EMBO J] 1995 Dec 01; Vol. 14 (23), pp. 5869-83. - Publication Year :
- 1995
-
Abstract
- Human furin catalyzes the proteolytic maturation of many proproteins in the exocytic and endocytic secretory pathways by cleavage at the C-terminal side of the consensus sequence-ArgXaaLys/ArgArg decreases -. Both the trans-Golgi network (TGN) concentration and intracellular routing of furin require sequences in its 56 amino acid cytoplasmic tail. Here, we show that the furin cytoplasmic tail contains multiple trafficking signals. Localization to the TGN requires a cluster of acidic amino acids that, together with a pair of serine residues, forms a casein kinase II (CK II) phosphorylation site. We show that CK II efficiently phosphorylates these serines in vitro, and using a permeabilized cell system we provide evidence that CK II is the in vivo furin kinase. Analysis by mass spectrometry shows that, in vivo, furin exists as di-, mono- and non-phosphorylated forms. Finally, employing (i) furin constructs that mimic either non-phosphorylated or phosphorylated furin and (ii) the phosphatase inhibitor tautomycin, we show that the phosphorylation state of the furin cytoplasmic tail modulates retrieval of the endoprotease to the TGN. Thus, routing of furin is a two-tiered process combining a set of trafficking signals comprised of the primary amino acid sequence of the tail with its phosphorylation state.
- Subjects :
- Amino Acid Sequence
Casein Kinase II
Cell Line
Cloning, Molecular
Cytoplasm metabolism
Endosomes enzymology
Endosomes metabolism
Fluorescent Antibody Technique
Furin
Golgi Apparatus metabolism
Humans
Mass Spectrometry
Molecular Sequence Data
Mutagenesis, Site-Directed genetics
Peptide Fragments chemistry
Peptide Fragments metabolism
Phosphoric Monoester Hydrolases antagonists & inhibitors
Phosphorylation
Protein Processing, Post-Translational genetics
Recombinant Fusion Proteins genetics
Serine metabolism
Subtilisins chemistry
Transferrin metabolism
Protein Serine-Threonine Kinases metabolism
Subtilisins metabolism
Subjects
Details
- Language :
- English
- ISSN :
- 0261-4189
- Volume :
- 14
- Issue :
- 23
- Database :
- MEDLINE
- Journal :
- The EMBO journal
- Publication Type :
- Academic Journal
- Accession number :
- 8846780
- Full Text :
- https://doi.org/10.1002/j.1460-2075.1995.tb00275.x