TY - JOUR
T1 - Structural organization of nuclear lamins A, C, B1, and B2 revealed by superresolution microscopy
AU - Shimia, Takeshi
AU - Kittisopikul, Mark
AU - Tran, Joseph
AU - Goldman, Anne E.
AU - Adam, Stephen A.
AU - Zheng, Yixian
AU - Jaqaman, Khuloud
AU - Goldman, Robert D.
N1 - Publisher Copyright:
© 2015 Shimi, Kittisopikul, et al.
PY - 2015/11/5
Y1 - 2015/11/5
N2 - The nuclear lamina is a key structural element of the metazoan nucleus. However, the structural organization of the major proteins composing the lamina is poorly defined. Using three-dimensional structured illumination microscopy and computational image analysis, we characterized the supramolecular structures of lamin A, C, B1, and B2 in mouse embryo fibroblast nuclei. Each isoform forms a distinct fiber meshwork, with comparable physical characteristics with respect to mesh edge length, mesh face area and shape, and edge connectivity to form faces. Some differences were found in face areas among isoforms due to variation in the edge lengths and number of edges per face, suggesting that each meshwork has somewhat unique assembly characteristics. In fibroblasts null for the expression of either lamins A/C or lamin B1, the remaining lamin meshworks are altered compared with the lamin meshworks in wild-type nuclei or nuclei lacking lamin B2. Nuclei lacking LA/C exhibit slightly enlarged meshwork faces and some shape changes, whereas LB1-deficient nuclei exhibit primarily a substantial increase in face area. These studies demonstrate that individual lamin isoforms assemble into complex networks within the nuclear lamina and that A-and B-type lamins have distinct roles in maintaining the organization of the nuclear lamina.
AB - The nuclear lamina is a key structural element of the metazoan nucleus. However, the structural organization of the major proteins composing the lamina is poorly defined. Using three-dimensional structured illumination microscopy and computational image analysis, we characterized the supramolecular structures of lamin A, C, B1, and B2 in mouse embryo fibroblast nuclei. Each isoform forms a distinct fiber meshwork, with comparable physical characteristics with respect to mesh edge length, mesh face area and shape, and edge connectivity to form faces. Some differences were found in face areas among isoforms due to variation in the edge lengths and number of edges per face, suggesting that each meshwork has somewhat unique assembly characteristics. In fibroblasts null for the expression of either lamins A/C or lamin B1, the remaining lamin meshworks are altered compared with the lamin meshworks in wild-type nuclei or nuclei lacking lamin B2. Nuclei lacking LA/C exhibit slightly enlarged meshwork faces and some shape changes, whereas LB1-deficient nuclei exhibit primarily a substantial increase in face area. These studies demonstrate that individual lamin isoforms assemble into complex networks within the nuclear lamina and that A-and B-type lamins have distinct roles in maintaining the organization of the nuclear lamina.
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U2 - 10.1091/mbc.E15-07-0461
DO - 10.1091/mbc.E15-07-0461
M3 - Article
C2 - 26310440
AN - SCOPUS:84946762480
SN - 1059-1524
VL - 26
SP - 4075
EP - 4086
JO - Molecular biology of the cell
JF - Molecular biology of the cell
IS - 22
ER -