Morisawa G, Han-Yama A, Moda I, Tamai A, Iwabuchi M, Meshi T
Department of Botany, Graduate School of Science, Kyoto University, Sakyo-ku, Kyoto 606-8502, Japan.
Plant Cell. 2000 Oct;12(10):1903-16. doi: 10.1105/tpc.12.10.1903.
Interactions between the nuclear matrix and special regions of chromosomal DNA called matrix attachment regions (MARs) have been implicated in various nuclear functions. We have identified a novel protein from wheat, AT hook-containing MAR binding protein1 (AHM1), that binds preferentially to MARs. A multidomain protein, AHM1 has the special combination of a J domain-homologous region and a Zn finger-like motif (a J-Z array) and an AT hook. For MAR binding, the AT hook at the C terminus was essential, and an internal portion containing the Zn finger-like motif was additionally required in vivo. AHM1 was found in the nuclear matrix fraction and was localized in the nucleoplasm. AHM1 fused to green fluorescent protein had a speckled distribution pattern inside the nucleus. AHM1 is most likely a nuclear matrix component that functions between intranuclear framework and MARs. J-Z arrays can be found in a group of (hypothetical) proteins in plants, which may share some functions, presumably to recruit specific Hsp70 partners as co-chaperones.
核基质与被称为基质附着区域（MARs）的染色体DNA特殊区域之间的相互作用与多种核功能有关。我们从小麦中鉴定出一种新型蛋白质，含AT钩的MAR结合蛋白1（AHM1），它优先与MARs结合。AHM1是一种多结构域蛋白，具有J结构域同源区域、锌指样基序（J-Z阵列）和AT钩的特殊组合。对于MAR结合，C末端的AT钩至关重要，并且体内还需要包含锌指样基序的内部部分。AHM1存在于核基质组分中，并定位于核质中。与绿色荧光蛋白融合的AHM1在细胞核内具有斑点状分布模式。AHM1很可能是一种在核内框架和MARs之间起作用的核基质成分。J-Z阵列可以在植物中的一组（假设的）蛋白质中找到，它们可能具有一些共同功能，大概是招募特定的Hsp70伴侣作为共伴侣。
