Bao Xiaomin, Girton Jack, Johansen Jørgen, Johansen Kristen M
Department of Biochemistry, Biophysics, and Molecular Biology, Iowa State University, 3154 Molecular Biology Building, Ames, Iowa 50011, USA.
Genetica. 2007 Mar;129(3):339-42. doi: 10.1007/s10709-006-0012-7. Epub 2006 Aug 1.
The association of lamin and lamin binding proteins with peripheral heterochromatin suggests the possibility that lamins may influence gene expression by participating in the epigenetic regulation of chromatin stucture. To test this hypothesis we have examined the effect of a recently generated partial loss-of-function lamin Dm0 allele Ari3 on PEV of the wm4 allele in the Drosophila eye. The Lam ( Ari3 ) allele is characterized by a truncation of the COOH-terminal domain and lacks the CaaX box that localizes lamin to the inner nuclear membrane. We show that the Lam ( Ari3 ) allele strongly increased silencing of wm4 expression, thus acting as an enhancer of PEV. These results indicate that lamins may be involved in regulating gene silencing and heterochromatic spreading at the wm4 locus and provide evidence that lamins may contribute to the regulation of higher-order chromatin organization.
核纤层蛋白及核纤层结合蛋白与外周异染色质的关联表明，核纤层蛋白可能通过参与染色质结构的表观遗传调控来影响基因表达。为了验证这一假设，我们研究了果蝇眼中最近产生的部分功能丧失的核纤层蛋白Dm0等位基因Ari3对wm4等位基因位置效应斑驳（PEV）的影响。Lam（Ari3）等位基因的特征是COOH末端结构域截断，并且缺乏将核纤层蛋白定位到内核膜的CaaX框。我们发现Lam（Ari3）等位基因强烈增强了wm4表达的沉默，从而起到PEV增强子的作用。这些结果表明，核纤层蛋白可能参与调控wm4位点的基因沉默和异染色质扩展，并提供了核纤层蛋白可能有助于调控高阶染色质组织的证据。
