Gao Zhengliang, Schwartz Lawrence M
Molecular and Cellular Biology Program, University of Massachusetts, Amherst, 01003, USA.
FEBS Lett. 2005 Oct 24;579(25):5651-7. doi: 10.1016/j.febslet.2005.08.086. Epub 2005 Sep 29.
Hic-5/ARA55 is a LIM-only member of the paxillin superfamily. Conflicting reports have suggested that Hic-5/ARA55 can both repress and enhance a number of biological processes, including myogenesis and tumorigenesis. With two Hic-5 isoforms documented, we hypothesized that multiple Hic-5 isoforms may exist that have both overlapping and isoform-specific functions. To test this hypothesis, we performed an extensive analysis of Hic-5 transcripts in both cell lines and mouse tissues and found 12 distinct isoforms that fall into two sub-families. These isoforms are derived from both alternative splicing and alternative transcriptional start sites (TSS). Hic-5 expression is regulated in a temporally and spatially controlled manner in vivo. The identification of numerous Hic-5 isoforms suggests that Hic-5 subsumes a number of distinct roles in cells and may explain the range of biological responses attributed to Hic-5.
Hic-5/ARA55是桩蛋白超家族中仅含LIM结构域的成员。相互矛盾的报道表明，Hic-5/ARA55既能抑制也能促进包括肌发生和肿瘤发生在内的多种生物学过程。已有两种Hic-5亚型被记录，我们推测可能存在多种具有重叠功能和亚型特异性功能的Hic-5亚型。为了验证这一假设，我们对细胞系和小鼠组织中的Hic-5转录本进行了广泛分析，发现了12种不同的亚型，它们分为两个亚家族。这些亚型来源于可变剪接和可变转录起始位点（TSS）。在体内，Hic-5的表达受到时间和空间的调控。众多Hic-5亚型的鉴定表明，Hic-5在细胞中具有多种不同的作用，这可能解释了归因于Hic-5的一系列生物学反应。
