A-type and B-type lamins initiate layer assembly at distinct areas of the nuclear envelope in living cells.
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.
Furukawa
Kazuhiro
K
Department of Chemistry, Faculty of Science, Niigata University, Niigata 950-2181, Japan. furukawa@chem.sc.niigata-u.ac.jp
Ishida
Kazuya
K
Tsunoyama
Taka-aki
TA
Toda
Suguru
S
Osoda
Shinichi
S
Horigome
Tsuneyoshi
T
Fisher
Paul A
PA
Sugiyama
Shin
S
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
D029721:Drosophila Proteins; D034904:Lamin Type A; D034921:Lamin Type B; D020033:Protein Isoforms; D011993:Recombinant Fusion Proteins