title: Characterization of plant proliferating cell nuclear antigen (PCNA) and flap endonuclease-1 (FEN-1), and their distribution in mitotic and meiotic cell cycles.
abstract: The biochemical and cell cycle-dependent properties of proliferating cell nuclear antigen (OsPCNA) and flap endonuclease-1 (OsFEN-1) were characterized from rice (Oryza sativa). OsPCNA was physically associated with OsFEN-1 and increased the flap-endonuclease activity of OsFEN-1 by 2.5-fold. Northern and Western blotting analysis revealed that OsPCNA and OsFEN-1 were present in meristematic tissues such as cultured cells, shoot apical meristem and root apical meristem. No expression was detected in the mature leaves, although they were exposed to UV. Both of these proteins were localized in the nuclei of the interphase cells including G1, S and G2, and in the nuclear region at telophase. The distribution patterns of plant PCNA and FEN-1 in meiotic cell progression were investigated using microsporocytes of lily (Lilium longiflorum cv. Hinomoto). During the leptotene to pachytene stages, PCNA and FEN-1 were localized in the nuclear region. The florescence gradually disappeared from diplotene to metaphase I. Interestingly, signals for PCNA formed 10-20 intense spots at leptotene. The number of spots decreased to 1-5 at zygotene and finally to 1 at pachytene. The roles of OsPCNA and OsFEN-1 in mitotic and meiotic cell cycles are discussed.
authors.affiliation: Department of Applied Biological Science, Faculty of Science and Technology, Tokyo University of Science, 2641 Yamazaki, Noda-shi, Chiba-ken 278, Japan.
authors.forename: S
authors.initials: S
authors.lastname: Kimura
authors.forename: T
authors.initials: T
authors.lastname: Suzuki
authors.forename: Y
authors.initials: Y
authors.lastname: Yanagawa
authors.forename: T
authors.initials: T
authors.lastname: Yamamoto
authors.forename: H
authors.initials: H
authors.lastname: Nakagawa
authors.forename: I
authors.initials: I
authors.lastname: Tanaka
authors.forename: J
authors.initials: J
authors.lastname: Hashimoto
authors.forename: K
authors.initials: K
authors.lastname: Sakaguchi
mesh_terms: D000906:Antibodies / Q000276:immunology; D002460:Cell Line; D003429:Cross Reactions; D004706:Endodeoxyribonucleases / Q000378:metabolism*; D045585:Flap Endonucleases; D008540:Meiosis; D008938:Mitosis; D059828:Plant Cells; D010944:Plants / Q000201:enzymology* / Q000276:immunology*; D018809:Proliferating Cell Nuclear Antigen / Q000378:metabolism*; D013347:Subcellular Fractions / Q000201:enzymology / Q000276:immunology
chemical_list: D000906:Antibodies; D018809:Proliferating Cell Nuclear Antigen; D004706:Endodeoxyribonucleases; D045585:Flap Endonucleases