title: Phosphorylation of p97(VCP) and p47 in vitro by p34cdc2 kinase.
abstract: The hexameric ATPase p97/yeast Cdc48p has been implicated in a number of cellular events that are regulated during mitosis, including homotypic membrane fusion, spindle pole body function, and ubiquitin-dependent protein degradation. p97/Cdc48p contains two conserved consensus p34cdc2 kinase phosphorylation sites within its second ATP binding domain. This domain is likely to play a role in stabilising the hexameric form of the protein. We therefore investigated whether p97 could be phosphorylated by p34cdc2 kinase in vitro, and whether phosphorylation might influence the oligomeric status of p97. Monomeric, but not hexameric, p97 was phosphorylated by p34cdc2 kinase, as was the p97-associated protein p47. However, phosphorylation by p34cdc2 kinase did not impair subsequent re-hexamerisation of p97, implying that the phosphorylated residue(s) are not critical for interaction between p97 monomers. Moreover, p97 within both interphase and mitotic cytosols was almost exclusively hexameric, suggesting that the activity of p97 is not regulated during mitosis by influencing the extent of oligomerisation.
authors.affiliation: School of Biological Sciences, University of Manchester, UK.
authors.forename: P S
authors.initials: PS
authors.lastname: Mayr
authors.forename: V J
authors.initials: VJ
authors.lastname: Allan
authors.forename: P G
authors.initials: PG
authors.lastname: Woodman
mesh_terms: D000251:Adenosine Triphosphatases; D000818:Animals; D001921:Brain / Q000378:metabolism; D016203:CDC2 Protein Kinase / Q000502:physiology*; D002352:Carrier Proteins / Q000502:physiology*; D018797:Cell Cycle Proteins / Q000502:physiology*; D006367:HeLa Cells; D006801:Humans; D066298:In Vitro Techniques; D008565:Membrane Proteins / Q000502:physiology*; D010063:Ovum / Q000378:metabolism; D010766:Phosphorylation; D052067:Soluble N-Ethylmaleimide-Sensitive Factor Attachment Proteins; D013552:Swine; D000074405:Valosin Containing Protein; D033921:Vesicular Transport Proteins; D014981:Xenopus / Q000196:embryology
chemical_list: D002352:Carrier Proteins; D018797:Cell Cycle Proteins; D008565:Membrane Proteins; D052067:Soluble N-Ethylmaleimide-Sensitive Factor Attachment Proteins; D033921:Vesicular Transport Proteins; D016203:CDC2 Protein Kinase; D000251:Adenosine Triphosphatases; C000614178:VCP protein, human; D000074405:Valosin Containing Protein