AP-1 recruitment to VAMP4 is modulated by phosphorylation-dependent binding of PACS-1.
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.
Hinners
Ina
I
Cancer Research UK, London Research Institute, 44 Lincoln's Inn Fields, London WC2A 3PX, UK.
Wendler
Franz
F
Fei
Hao
H
Thomas
Laurel
L
Thomas
Gary
G
Tooze
Sharon A
SA
D033961:Adaptor Protein Complex 1 / Q000737:chemistry / Q000378:metabolism*; D033942:Adaptor Proteins, Vesicular Transport / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D000324:Adrenocorticotropic Hormone / Q000378:metabolism; D020816:Amino Acid Motifs; D000818:Animals; D002352:Carrier Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D047390:Casein Kinase II; D002460:Cell Line; D006160:Guanosine Triphosphate / Q000378:metabolism; D007930:Leucine / Q000737:chemistry / Q000378:metabolism; D008565:Membrane Proteins / Q000378:metabolism; D051379:Mice; D009154:Mutation; D010766:Phosphorylation; D011485:Protein Binding; D017346:Protein Serine-Threonine Kinases / Q000378:metabolism; D050683:R-SNARE Proteins; D050600:SNARE Proteins; D012694:Serine / Q000737:chemistry / Q000378:metabolism; D014162:Transfection; D033921:Vesicular Transport Proteins; D021601:trans-Golgi Network
D033961:Adaptor Protein Complex 1; D033942:Adaptor Proteins, Vesicular Transport; D002352:Carrier Proteins; D008565:Membrane Proteins; C491913:Pacs1 protein, mouse; D050683:R-SNARE Proteins; D050600:SNARE Proteins; C476457:Vamp4 protein, mouse; D033921:Vesicular Transport Proteins; D012694:Serine; D006160:Guanosine Triphosphate; D000324:Adrenocorticotropic Hormone; D047390:Casein Kinase II; D017346:Protein Serine-Threonine Kinases; D007930:Leucine