AP-1 recruitment to VAMP4 is modulated by phosphorylation-dependent binding of PACS-1

EMBO Rep. 2003 Dec;4(12):1182-9. doi: 10.1038/sj.embor.7400018. Epub 2003 Nov 7.

Abstract

The R-SNARE VAMP4, which contains a dileucine motif, binds to the AP-1 (adaptor protein-1) subunit mu 1a, but not mu 1b, or the GGAs (Golgi-associated gamma ear containing ARF binding proteins). Serine 20 and leucines 25,26 are essential for this binding. AP-1 association with VAMP4 is enhanced when serine 30, in an acidic cluster, is phosphorylated by casein kinase 2. This phosphorylation-dependent modulation of AP-1 binding is mediated by PACS-1 (phosphofurin acidic cluster sorting protein). Ablation of both the dileucine motif and serine 30 results in a dramatic mislocalization of VAMP4 in the regulated secretory pathway in AtT20 cells. A dominant-negative PACS-1, which binds acidic clusters but not AP-1, also causes mislocalization of VAMP4. Our data support a model whereby phosphorylation-dependent recruitment of PACS-1 enhances AP-1 association to cargo, and suggest that efficient retrieval depends on the formation of a complex between cargo, such as VAMP4, AP-1 and PACS-1.

Publication types

  • Comparative Study
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Adaptor Protein Complex 1 / chemistry
  • Adaptor Protein Complex 1 / metabolism*
  • Adaptor Proteins, Vesicular Transport / chemistry
  • Adaptor Proteins, Vesicular Transport / genetics
  • Adaptor Proteins, Vesicular Transport / metabolism*
  • Adrenocorticotropic Hormone / metabolism
  • Amino Acid Motifs
  • Animals
  • Carrier Proteins / chemistry
  • Carrier Proteins / genetics
  • Carrier Proteins / metabolism*
  • Casein Kinase II
  • Cell Line
  • Guanosine Triphosphate / metabolism
  • Leucine / chemistry
  • Leucine / metabolism
  • Membrane Proteins / metabolism
  • Mice
  • Mutation
  • Phosphorylation
  • Protein Binding
  • Protein-Serine-Threonine Kinases / metabolism
  • R-SNARE Proteins
  • SNARE Proteins
  • Serine / chemistry
  • Serine / metabolism
  • Transfection
  • Vesicular Transport Proteins*
  • trans-Golgi Network

Substances

  • Adaptor Protein Complex 1
  • Adaptor Proteins, Vesicular Transport
  • Carrier Proteins
  • Membrane Proteins
  • Pacs1 protein, mouse
  • R-SNARE Proteins
  • SNARE Proteins
  • Vamp4 protein, mouse
  • Vesicular Transport Proteins
  • Serine
  • Guanosine Triphosphate
  • Adrenocorticotropic Hormone
  • Casein Kinase II
  • Protein-Serine-Threonine Kinases
  • Leucine