Nesprin-2 giant safeguards nuclear envelope architecture in LMNA S143F progeria cells.
The S143F lamin A/C point mutation causes a phenotype combining features of myopathy and progeria. We demonstrate here that patient dermal fibroblast cells have dysmorphic nuclei containing numerous blebs and lobulations, which progressively accumulate as cells age in culture. The lamin A/C organization is altered, showing intranuclear and nuclear envelope (NE) aggregates and presenting often a honeycomb appearance. Immunofluorescence microscopy showed that nesprin-2 C-terminal isoforms and LAP2alpha were recovered in the cytoplasm, whereas LAP2beta and emerin were unevenly localized along the NE. In addition, the intranuclear organization of acetylated histones, histone H1 and the active form of RNA polymerase II were markedly different in patient cells. A subpopulation of mutant cells, however, expressing the 800 kDa nesprin-2 giant isoform, did not show an overt nuclear phenotype. Ectopic expression of p.S143F lamin A in fibroblasts recapitulates the patient cell phenotype, whereas no effects were observed in p.S143F LMNA keratinocytes, which highly express nesprin-2 giant. Overexpression of the mutant lamin A protein had a more severe impact on the NE of nesprin-2 giant deficient fibroblasts when compared with wild-type. In summary, our results suggest that the p.S143F lamin A mutation affects NE architecture and composition, chromatin organization, gene expression and transcription. Furthermore, our findings implicate a direct involvement of the nesprins in laminopathies and propose nesprin-2 giant as a structural reinforcer at the NE.
Kandert
Sebastian
S
Department of Cell and Developmental Biology, University of Würzburg, D97074, Würzburg, Germany.
Lüke
Yvonne
Y
Kleinhenz
Tobias
T
Neumann
Sascha
S
Lu
Wenshu
W
Jaeger
Verena M
VM
Munck
Martina
M
Wehnert
Manfred
M
Müller
Clemens R
CR
Zhou
Zhongjun
Z
Noegel
Angelika A
AA
Dabauvalle
Marie-Christine
MC
Karakesisoglou
Iakowos
I
D000595:Amino Acid Sequence; D001483:Base Sequence; D002478:Cells, Cultured; D002843:Chromatin / Q000378:metabolism; D017931:DNA Primers / Q000235:genetics; D005260:Female; D005347:Fibroblasts / Q000378:metabolism / Q000473:pathology; D017353:Gene Deletion; D006801:Humans; D034904:Lamin Type A / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism; D008565:Membrane Proteins / Q000172:deficiency / Q000235:genetics; D008666:Metalloendopeptidases / Q000172:deficiency / Q000235:genetics; D008840:Microfilament Proteins / Q000172:deficiency / Q000235:genetics / Q000378:metabolism*; D008969:Molecular Sequence Data; D009419:Nerve Tissue Proteins / Q000172:deficiency / Q000235:genetics / Q000378:metabolism*; D009685:Nuclear Envelope / Q000378:metabolism* / Q000473:pathology; D009687:Nuclear Proteins / Q000172:deficiency / Q000235:genetics / Q000378:metabolism*; D010641:Phenotype; D017354:Point Mutation; D011371:Progeria / Q000235:genetics* / Q000378:metabolism* / Q000473:pathology; D017386:Sequence Homology, Amino Acid; D014158:Transcription, Genetic
D002843:Chromatin; D017931:DNA Primers; C494847:LMNA protein, human; D034904:Lamin Type A; D008565:Membrane Proteins; D008840:Microfilament Proteins; D009419:Nerve Tissue Proteins; D009687:Nuclear Proteins; C485904:SYNE2 protein, human; D008666:Metalloendopeptidases; C120130:ZMPSTE24 protein, human