title: Mapping the functional domains of the Golgi stacking factor GRASP65.
abstract: The Golgi reassembly stacking protein (GRASP) family has been implicated in the stacking of Golgi cisternae and the regulation of Golgi disassembly/reassembly during mitosis in mammalian cells. GRASP65 is a dimer that can directly link adjacent surfaces through trans-oligomerization in a mitotically regulated manner. Here we show that the N-terminal GRASP domain (amino acids 1-201) is both necessary and sufficient for dimerization and trans-oligomerization but is not mitotically regulated. The C-terminal serine/proline-rich domain (amino acids 202-446) cannot dimerize nor can it link adjacent surfaces. It does, however, confer mitotic regulation on the GRASP domain through multiple sites phosphorylated by the mitotic kinases, cdc2/B1, and the polo-like kinase. Transient expression corroborated these results by showing that the GRASP domain alone inhibited mitotic fragmentation of the Golgi apparatus.
authors.affiliation: Department of Cell Biology, Ludwig Institute for Cancer Research, Yale University School of Medicine, New Haven, Connecticut 06520, USA. yanzhuang.wang@yale.edu
authors.forename: Yanzhuang
authors.initials: Y
authors.lastname: Wang
authors.forename: Ayano
authors.initials: A
authors.lastname: Satoh
authors.forename: Graham
authors.initials: G
authors.lastname: Warren
mesh_terms: D001665:Binding Sites; D042846:CDC2-CDC28 Kinases / Q000378:metabolism; D018797:Cell Cycle Proteins; D003600:Cytosol / Q000378:metabolism; D019281:Dimerization; D005982:Glutathione Transferase / Q000378:metabolism; D006056:Golgi Apparatus / Q000378:metabolism*; D000077614:Golgi Matrix Proteins; D049452:Green Fluorescent Proteins / Q000378:metabolism; D006367:HeLa Cells; D006801:Humans; D008565:Membrane Proteins / Q000737:chemistry* / Q000378:metabolism; D008938:Mitosis; D010766:Phosphorylation; D011392:Proline / Q000737:chemistry; D011485:Protein Binding; D011494:Protein Kinases / Q000378:metabolism; D017346:Protein Serine-Threonine Kinases; D017434:Protein Structure, Tertiary; D011518:Proto-Oncogene Proteins; D011993:Recombinant Fusion Proteins / Q000737:chemistry; D012694:Serine / Q000737:chemistry; D000097869:Polo-Like Kinase 1
chemical_list: D042846:CDC2-CDC28 Kinases; D018797:Cell Cycle Proteins; D005982:Glutathione Transferase; D000077614:Golgi Matrix Proteins; D049452:Green Fluorescent Proteins; D008565:Membrane Proteins; D011392:Proline; D011494:Protein Kinases; D017346:Protein Serine-Threonine Kinases; D011518:Proto-Oncogene Proteins; D011993:Recombinant Fusion Proteins; D012694:Serine; D000097869:Polo-Like Kinase 1; C108705:GORASP1 protein, human