Mapping of Nuclear Matrix Binding Region of Human Genome and Functional Analysis of A Nuclear Matrix Protein

我们研究了大鼠核支架蛋白P130的分子基础及其功能。P130由845个氨基酸残基组成，具有几个功能域，并通过改变其磷酸化状态，从而产生一个电泳上独特的异构体P123，该磷酸化状态与核膜上的易位以及从洋地黄苷可提取的细胞核部分到核支架的易位有关。NLS、NES和含锌指的dna结合结构域ZF1和ZF2有助于这些易位。P130通过与hnRNPs I和l类似的两个RNA结合结构域（RB1和RB2）结合RNA。在大鼠肝脏和Ac2F肝癌细胞中发现了微体和多体定位的P130和P123。这种定位需要P130事先进入细胞核，但不需要RB1和RB2。因此，最初从大鼠肝核支架中纯化的P130不仅在核支架中，而且在各种亚细胞区室中都有可能在生物事件中发挥多种作用。P130 （AB205483）与matrin 3 （M63485和BC062231）相同，尽管大鼠matrin 3的主要结构自首次发表以来已被修改。人类基因组数据库（GDB） （Future et al. 2000; http::/ GDB www.gdb.org/）被用于MAR/SAR搜索程序[MARFinder或SMARTest (Friscm et al. 2002; http://www.genomatix.de/cgi-bin/smartest pd/smartest.pl)]，因此，我们已经绘制了人类基因组中30个基因的100多个MARs/SAR。

We examined the molecular basis of rat P130, a nuclear scaffold protein, and its functions. P130 comprising 845 amino acid residues possesses several functional domains and yields an electrophoretically distinctive isoform, P123, by altering its phosphorylation status in association with translocation across the nuclear membrane and from the digitonin-extractable fraction of the nucleus to the nuclear scaffold. The functional domains, NLS, NES, and zinc-finger bearing DNA-binding domains, ZF1 and ZF2, aid these translocations. P130 binds RNA through two RNA-binding domains (RB1 and RB2) similar to those of hnRNPs I and L.Microsome- and polysome-localized P130 and P123 were found in rat liver and Ac2F hepatoma cells. This localization required prior entry of P130 to the nucleus, but did not require RB1 and RB2. Thus, P130 initially purified from rat liver nuclear scaffold has the potential to play a variety of roles in biological events not only in the nuclear scaffold but also in various subcellular compartments. P130 (AB205483) is identical to matrin 3 (M63485 and BC062231), although the primary structure of rat matrin 3 has been revised, since it was first published.The Human Genome Database (GDB) (Future et al. 2000 ; http::/gdbwww.gdb.org/) was used for MAR/SAR search program [MARFinder or SMARTest (Friscm et al. 2002 ; http://www.genomatix.de/cgi-bin/smartest pd/smartest.pl)] As a consequence, we have mapped more than 100 MARs/SARs of 30 genes in human genome.