Ye Q, Worman H J
Department of Medicine, College of Physicians and Surgeons, Columbia University, New York, New York 10032, USA.
J Biol Chem. 1996 Jun 21;271(25):14653-6. doi: 10.1074/jbc.271.25.14653.
At the nuclear envelope in higher eukaryotic cells, the nuclear lamina and the heterochromatin are adjacent to the inner nuclear membrane, and their attachment is presumably mediated by integral membrane proteins. In a yeast two-hybrid screen, the nucleoplasmic domain of lamin B receptor (LBR), an integral protein of the inner nuclear membrane, associated with two human polypeptides homologous to Drosophila HP1, a heterochromatin protein involved in position-effect variegation. LBR fusion proteins bound to HP1 proteins synthesized by in vitro translation and present in cell lysates. Antibodies against LBR also co-immunoprecipitated HP1 proteins from cell extracts. LBR can interact with chromodomain proteins that are highly conserved in eukaryotic species and may function in the attachment of heterochromatin to the inner nuclear membrane in cells.
在高等真核细胞的核膜处，核纤层和异染色质与内核膜相邻，它们的附着可能是由整合膜蛋白介导的。在酵母双杂交筛选中，内核膜的整合蛋白核纤层蛋白B受体（LBR）的核质结构域，与两种与果蝇HP1同源的人类多肽相关，果蝇HP1是一种参与位置效应斑驳的异染色质蛋白。LBR融合蛋白与通过体外翻译合成并存在于细胞裂解物中的HP1蛋白结合。针对LBR的抗体也能从细胞提取物中共免疫沉淀HP1蛋白。LBR可以与在真核生物物种中高度保守的染色质结构域蛋白相互作用，并且可能在细胞中异染色质与内核膜的附着过程中发挥作用。
