LAP2α and BAF transiently localize to telomeres and specific regions on chromatin during nuclear assembly
LAP2α and BAF transiently localize to telomeres and specific regions on chromatin during nuclear assembly
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DOI：
10.1242/jcs.01529
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发表时间：
2004-12-01
影响因子：
4
通讯作者：
Foisner, R
中科院分区：
文献类型：
--
作者：
Dechat, T;Gajewski, A;Foisner, R
核纤层相关多肽（lamina-associated polypeptide，LEM）是核纤层相关多肽（lamina-associated polypeptide emerin MAN 1）家族中的一种蛋白质，与核质A型核纤层蛋白和染色质相关。使用活细胞成像和荧光显微镜，我们证明，LAP 2 α主要是在中期细胞质和相关的端粒在后期。端粒LAP 2 α簇的体积增大，在染色质上形成“核心”结构，并在G1期易位到核质中。核纤层蛋白C和核突蛋白的亚组分在早期跟随LAP 2 α到达核心区域，而LAP 2 β、核纤层蛋白B受体和核纤层蛋白B最初结合到染色质的更外围区域，然后以不同的动力学扩散到核心结构。此外，DNA交联蛋白屏障-自整合因子（BAF）结合到LAP 2 α在体外和有丝分裂提取物中，和BAF的亚组分重新定位到核心结构与LAP 2 α。我们建议，LAP 2 α和BAF的一个亚组分在染色质核心区域形成确定的复合物，并可能参与核组装早期阶段的染色质重组。
Lamina-associated polypeptide (LAP) 2alpha is a LEM (lamina-associated polypeptide emerin MAN1) family protein associated with nucleoplasmic A-type lamins and chromatin. Using live cell imaging and fluorescence microscopy we demonstrate that LAP2alpha was mostly cytoplasmic in metaphase and associated with telomeres in anaphase. Telomeric LAP2alpha clusters grew in size, formed 'core' structures on chromatin adjacent to the spindle in telophase, and translocated to the nucleoplasm in G1 phase. A subfraction of lamin C and emerin followed LAP2alpha to the core region early on, whereas LAP2beta, lamin B receptor and lamin B initially bound to more peripheral regions of chromatin, before they spread to core structures with different kinetics. Furthermore, the DNA-crosslinking protein barrier-to-autointegration factor (BAF) bound to LAP2alpha in vitro and in mitotic extracts, and subfractions of BAF relocalized to core structures with LAP2alpha. We propose that LAP2alpha and a subfraction of BAF form defined complexes in chromatin core regions and may be involved in chromatin reorganization during early stages of nuclear assembly.