title: Immunoelectron microscopic analysis of the intracellular distribution of primer recognition proteins, annexin 2 and phosphoglycerate kinase, in normal and transformed cells.
abstract: Primer recognition proteins (PRP) are accessory proteins for DNA polymerase alpha in lagging strand DNA replication. We have previously reported that the PRP consist of a complex of two proteins identified as 3-phosphoglycerate kinase (PGK) and the protein-tyrosine kinase substrate, annexin 2 monomer. The physiological role of annexin 2 is not known. Two pools of annexin 2 exist in cells. A majority of annexin 2 is localized with the plasma membrane as a heterotetramer in association with a light chain. Monomer annexin 2 is cytosolic. The identification of annexin 2 monomer as a part of the PRP complex represents one of the physiological roles of this protein in cells. To function as PRP, annexin 2 and PGK would have to be present in the cell nucleus. To investigate whether monomer annexin 2 is indeed associated with nuclear DNA synthesis, we investigated the presence of annexin 2 and PGK in the cell nucleus. In this paper, we demonstrate the presence of annexin 2 and PGK in nuclear extracts. The nuclear fraction of these proteins represents a small subset of the total cellular pools. Immunoelectron-microscopic analyses using anti-PRP antisera demonstrate the distribution of these proteins in HeLa cell nuclei and cytoplasm. Under identical conditions, an anti-cytokeratin monoclonal antibody preferentially labels the plasma membrane without detectable intracellular staining. The distribution of annexin 2 and PGK in both nuclei and cytoplasm is similarly observed in cells from normal tissues such as freshly isolated rat hepatocytes and hamster pancreatic tissue.(ABSTRACT TRUNCATED AT 250 WORDS)
authors.affiliation: Department of Biochemistry, University of Nebraska Medical Center, Omaha 68198-4525.
authors.forename: K D
authors.initials: KD
authors.lastname: Kumble
authors.forename: J K
authors.initials: JK
authors.lastname: Vishwanatha
mesh_terms: D000818:Animals; D017302:Annexins; D002135:Calcium-Binding Proteins / Q000032:analysis*; D002453:Cell Cycle; D002462:Cell Membrane / Q000737:chemistry; D002467:Cell Nucleus / Q000737:chemistry* / Q000201:enzymology; D002471:Cell Transformation, Neoplastic; D006224:Cricetinae; D003593:Cytoplasm / Q000737:chemistry* / Q000201:enzymology; D004261:DNA Replication; D006367:HeLa Cells; D006801:Humans; D008099:Liver / Q000737:chemistry / Q000648:ultrastructure; D008565:Membrane Proteins / Q000032:analysis*; D016253:Microscopy, Immunoelectron; D010179:Pancreas / Q000737:chemistry / Q000648:ultrastructure; D010735:Phosphoglycerate Kinase / Q000032:analysis*; D051381:Rats
chemical_list: D017302:Annexins; D002135:Calcium-Binding Proteins; D008565:Membrane Proteins; D010735:Phosphoglycerate Kinase