A-type lamins bind both hetero-and euchromatin, the latter being regulated by lamina-associated polypeptide 2 alpha

K Gesson, P Rescheneder, MP Skoruppa… - Genome …, 2016 - genome.cshlp.org
K Gesson, P Rescheneder, MP Skoruppa, A von Haeseler, T Dechat, R Foisner
Genome research, 2016genome.cshlp.org
Lamins are components of the peripheral nuclear lamina and interact with heterochromatic
genomic regions, termed lamina-associated domains (LADs). In contrast to lamin B1 being
primarily present at the nuclear periphery, lamin A/C also localizes throughout the nucleus,
where it associates with the chromatin-binding protein lamina-associated polypeptide (LAP)
2 alpha. Here, we show that lamin A/C also interacts with euchromatin, as determined by
chromatin immunoprecipitation of euchromatin-and heterochromatin-enriched samples. By …
Lamins are components of the peripheral nuclear lamina and interact with heterochromatic genomic regions, termed lamina-associated domains (LADs). In contrast to lamin B1 being primarily present at the nuclear periphery, lamin A/C also localizes throughout the nucleus, where it associates with the chromatin-binding protein lamina-associated polypeptide (LAP) 2 alpha. Here, we show that lamin A/C also interacts with euchromatin, as determined by chromatin immunoprecipitation of euchromatin- and heterochromatin-enriched samples. By way of contrast, lamin B1 was only found associated with heterochromatin. Euchromatic regions occupied by lamin A/C overlap with those bound by LAP2alpha, and lack of LAP2alpha in LAP2alpha-deficient cells shifts binding of lamin A/C toward more heterochromatic regions. These alterations in lamin A/C-chromatin interactions correlate with changes in epigenetic histone marks in euchromatin but do not significantly affect gene expression. Loss of lamin A/C in heterochromatic regions in LAP2alpha-deficient cells, however, correlated with increased gene expression. Our data show a novel role of nucleoplasmic lamin A/C and LAP2alpha in regulating euchromatin.
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