Structural organization of nuclear lamins A, C, B1, and B2 revealed by superresolution microscopy

• DOI: 10.1091/mbc.e15-07-0461
• Publication Date: 2015-08-27T02:09:53Z
• Authors: Takeshi Shimi; Mark Kittisopikul; Joseph Tran; Anne E. Goldman; Stephen A. Adam; Yixian Zheng; Khuloud Jaqaman; Robert D. Goldman
• Keywords: Nuclear lamina; Lamina; Inner membrane; Immunoelectron microscopy

The nuclear lamina is a key structural element of the metazoan nucleus. However, organization major proteins composing poorly defined. Using three-dimensional structured illumination microscopy and computational image analysis, we characterized supramolecular structures lamin A, C, B1, B2 in mouse embryo fibroblast nuclei. Each isoform forms distinct fiber meshwork, with comparable physical characteristics respect to mesh edge length, face area shape, connectivity form faces. Some differences were found areas among isoforms due variation lengths number edges per face, suggesting that each meshwork has somewhat unique assembly characteristics. In fibroblasts null for expression either lamins A/C or remaining meshworks are altered compared wild-type nuclei lacking B2. Nuclei LA/C exhibit slightly enlarged faces some shape changes, whereas LB1-deficient primarily substantial increase area. These studies demonstrate individual assemble into complex networks within A- B-type have roles maintaining lamina.