Lamin B1 coordinates the assembly of the nuclear lamina
- 1Department of Medicine, University of California, Los Angeles, Los Angeles, CA 90095, USA
- 2Department of Human Genetics, University of California, Los Angeles, Los Angeles, CA 90095, USA
Abstract
The nuclear lamina provides essential mechanical stability to protect the genome; yet, how lamins target the nuclear rim and assemble into an organized meshwork remains unclear. To address this, we generated smooth muscle cells lacking all three lamin genes (Lmna, Lmnb1 and Lmnb2; ‘LKO cells’) and expressed individual lamins at physiological levels. All lamins localized to the nuclear rim but with distinct requirements: lamin B1 and lamin B2 required farnesylation, whereas prelamin A did not. Lamin C and mature lamin A also localized efficiently, demonstrating that C-terminal processing is not required for A-type lamin targeting. Despite correct targeting, lamins differed in their ability to form organized meshworks. Lamin B1 alone generated a normal fibrillar network, whereas lamin A, lamin C and lamin B2 formed disorganized structures with large gaps. Co-expression of lamin A and lamin C did not rescue this defect. In contrast, co-expression with lamin B1 restored proper meshwork organization for all lamins and was essential for nuclear lamina assembly during cell division. These findings identify lamin B1 as the central organizer of nuclear lamina architecture.
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BibTeX
@article{kim2026lamin,
title = {{Lamin B1 coordinates the assembly of the nuclear lamina}},
author = {JoonYoung R. Kim and Paul H. Kim and Yiping Tu and James Carroll and Jenna P. Koerner and Stephen G. Young and Loren G. Fong},
journal = {Journal of Cell Science},
year = {2026},
month = oct,
doi = {10.1242/jcs.265156},
url = {https://doi.org/10.1242/jcs.265156},
note = {CC BY 4.0},
}
RIS
TY - JOUR
TI - Lamin B1 coordinates the assembly of the nuclear lamina
AU - JoonYoung R. Kim
AU - Paul H. Kim
AU - Yiping Tu
AU - James Carroll
AU - Jenna P. Koerner
AU - Stephen G. Young
AU - Loren G. Fong
PY - 2026
DA - 2026/10/15
JO - Journal of Cell Science
DO - 10.1242/jcs.265156
UR - https://doi.org/10.1242/jcs.265156
AB - The nuclear lamina provides essential mechanical stability to protect the genome; yet, how lamins target the nuclear rim and assemble into an organized meshwork remains unclear. To address this, we generated smooth muscle cells lacking all three lamin genes (Lmna, Lmnb1 and Lmnb2; ‘LKO cells’) and expressed individual lamins at physiological levels. All lamins localized to the nuclear rim but with distinct requirements: lamin B1 and lamin B2 required farnesylation, whereas prelamin A did not. Lamin C and mature lamin A also localized efficiently, demonstrating that C-terminal processing is not required for A-type lamin targeting. Despite correct targeting, lamins differed in their ability to form organized meshworks. Lamin B1 alone generated a normal fibrillar network, whereas lamin A, lamin C and lamin B2 formed disorganized structures with large gaps. Co-expression of lamin A and lamin C did not rescue this defect. In contrast, co-expression with lamin B1 restored proper meshwork organization for all lamins and was essential for nuclear lamina assembly during cell division. These findings identify lamin B1 as the central organizer of nuclear lamina architecture.
SN - 0021-9533
SN - 1477-9137
ER -