title: Molecular cloning of a murine cDNA encoding a novel protein, p38-2G4, which varies with the cell cycle.
abstract: Proliferating cells express genes active in cell cycle control. The modulation of control genes and factors are required to maintain critical cell cycle activities. We used a set of monoclonal antibodies prepared against DNA-binding proteins from Ehrlich ascites tumor cells in immunofluorescent microscopy to screen for proteins showing cell cycle-specific staining patterns. Here, we report cloning and characterizing of a novel mitogen-inducible gene from murine macrophages that predicts a cell cycle-specifically modulated nuclear protein of 38 kDa, designated p38-2G4. p38-2G4 displayed a speckled pattern of varying fluorescence intensity confined to the nucleus, but sparing the nucleoli. Strongly stained granules were observed between G1 and mid S phase, followed by a less abundant punctated arrangement toward the end of S phase, and negative fluorescence at the S/G2 transition. Thereafter, the nuclear staining reappeared. Additionally, p38-2G4 expression vanished in G0-arrested cells and was restored after release from growth arrest. p38-2G4 conserved in vertebrates by means of immunofluorescence data contains a number of putative phosphorylation sites, a cryptic nuclear localization signal, and an amphipathic helical domain. Our cDNA and its deduced amino acid sequence is related to a Schizosaccharomyces pombe gene encoding a 42-kDa protein that associates with curved DNA, suggesting that we have cloned the murine homologue of the S. pombe gene which defines a novel cell cycle-specifically modified and proliferation-associated nuclear protein in mammals.
authors.affiliation: Institut für Genetik, Justus-Liebig-Universität, Giessen, Germany.
authors.forename: N
authors.initials: N
authors.lastname: Radomski
authors.forename: E
authors.initials: E
authors.lastname: Jost
mesh_terms: D016475:3T3 Cells; D000595:Amino Acid Sequence; D000818:Animals; D000911:Antibodies, Monoclonal; D001483:Base Sequence; D015153:Blotting, Western; D002286:Carcinoma, Ehrlich Tumor / Q000378:metabolism* / Q000473:pathology; D002453:Cell Cycle; D002467:Cell Nucleus / Q000378:metabolism / Q000648:ultrastructure; D003001:Cloning, Molecular; D004247:DNA / Q000737:chemistry / Q000235:genetics; D018076:DNA, Complementary / Q000378:metabolism; D004268:DNA-Binding Proteins / Q000032:analysis / Q000096:biosynthesis*; D019084:Fluorescent Antibody Technique, Indirect; D015870:Gene Expression; D015723:Gene Library; D006367:HeLa Cells; D006801:Humans; D007399:Interphase; D007700:Kinetics; D008264:Macrophages / Q000166:cytology / Q000378:metabolism; D051379:Mice; D008938:Mitosis; D008969:Molecular Sequence Data; D009687:Nuclear Proteins / Q000032:analysis / Q000096:biosynthesis*; D016601:RNA-Binding Proteins; D012568:Schizosaccharomyces / Q000378:metabolism; D017386:Sequence Homology, Amino Acid; D014407:Tumor Cells, Cultured
chemical_list: D000911:Antibodies, Monoclonal; D018076:DNA, Complementary; D004268:DNA-Binding Proteins; D009687:Nuclear Proteins; C095938:Pa2g4 protein, mouse; D016601:RNA-Binding Proteins; D004247:DNA