title: A perichromosomal region contains proteins phosphorylated during mitosis in Xenopus laevis cells.
abstract: An antibody that recognizes the phosphorylated form of nucleoplasmin has identified another nuclear protein whose antigenic form is regulated in a mitosis-specific manner, with a dramatic increase in binding occurring in all mitotic cells. The protein is localised around the periphery of condensed chromosomes during mitosis in a manner analogous to another nucleoplasmin-related polypeptide NO38. Mitosis-specific expression of the antigenic site is dependent on phosphorylation of the polypeptide; binding of the antibody is dramatically reduced by prior incubation of the polypeptide with phosphatases. Migration on SDS-PAGE suggests that the protein has an exceptionally large relative molecular mass, in excess of 400,000. The probable mitosis-specific phosphorylation and location of this antigen suggests a subcellular storage mechanism for proteins during mitosis.
authors.affiliation: CRC Molecular Embryology Research Group, Department of Zoology, Cambridge, UK.
authors.forename: S M
authors.initials: SM
authors.lastname: Dilworth
mesh_terms: D000818:Animals; D000911:Antibodies, Monoclonal; D002460:Cell Line; D002467:Cell Nucleus / Q000737:chemistry*; D002875:Chromosomes / Q000737:chemistry*; D003429:Cross Reactions; D004591:Electrophoresis, Polyacrylamide Gel; D008938:Mitosis; D008970:Molecular Weight; D009687:Nuclear Proteins / Q000032:analysis* / Q000737:chemistry / Q000276:immunology / Q000378:metabolism; D056489:Nucleoplasmins; D010750:Phosphoproteins; D010744:Phosphoric Monoester Hydrolases / Q000378:metabolism; D010766:Phosphorylation; D014982:Xenopus laevis
chemical_list: D000911:Antibodies, Monoclonal; D009687:Nuclear Proteins; D056489:Nucleoplasmins; D010750:Phosphoproteins; D010744:Phosphoric Monoester Hydrolases