title: A-type and B-type lamins initiate layer assembly at distinct areas of the nuclear envelope in living cells.
abstract: To investigate nuclear lamina re-assembly in vivo, Drosophila A-type and B-type lamins were artificially expressed in Drosophila lamin Dm(0)null mutant brain cells. Both exogenous lamin C (A-type) and Dm(0) (B-type) formed sub-layers at the nuclear periphery, and efficiently reverted the abnormal clustering of the NPC. Lamin C initially appeared where NPCs were clustered, and subsequently extended along the nuclear periphery accompanied by the recovery of the regular distribution of NPCs. In contrast, lamin Dm(0) did not show association with the clustered NPCs during lamina formation and NPC spacing recovered only after completion of a closed lamin Dm(0) layer. Further, when lamin Dm(0) and C were both expressed, they did not co-polymerize, initiating layer formation in separate regions. Thus, A and B-type lamins reveal differing properties during lamina assembly, with A-type having the primary role in organizing NPC distribution. This previously unknown complexity in the assembly of the nuclear lamina could be the basis for intricate nuclear envelope functions.
authors.affiliation: Department of Chemistry, Faculty of Science, Niigata University, Niigata 950-2181, Japan. furukawa@chem.sc.niigata-u.ac.jp
authors.forename: Kazuhiro
authors.initials: K
authors.lastname: Furukawa
authors.forename: Kazuya
authors.initials: K
authors.lastname: Ishida
authors.forename: Taka-aki
authors.initials: TA
authors.lastname: Tsunoyama
authors.forename: Suguru
authors.initials: S
authors.lastname: Toda
authors.forename: Shinichi
authors.initials: S
authors.lastname: Osoda
authors.forename: Tsuneyoshi
authors.initials: T
authors.lastname: Horigome
authors.forename: Paul A
authors.initials: PA
authors.lastname: Fisher
authors.forename: Shin
authors.initials: S
authors.lastname: Sugiyama
mesh_terms: D000818:Animals; D030801:Animals, Genetically Modified; D001921:Brain / Q000166:cytology / Q000378:metabolism; D029721:Drosophila Proteins / Q000235:genetics / Q000378:metabolism; D004331:Drosophila melanogaster / Q000166:cytology / Q000235:genetics / Q000378:metabolism; D034904:Lamin Type A / Q000235:genetics / Q000378:metabolism*; D034921:Lamin Type B / Q000235:genetics / Q000378:metabolism*; D009685:Nuclear Envelope / Q000378:metabolism*; D022022:Nuclear Pore / Q000378:metabolism; D020033:Protein Isoforms / Q000235:genetics / Q000378:metabolism*; D011993:Recombinant Fusion Proteins / Q000235:genetics / Q000378:metabolism
chemical_list: D029721:Drosophila Proteins; D034904:Lamin Type A; D034921:Lamin Type B; D020033:Protein Isoforms; D011993:Recombinant Fusion Proteins