HAX-1 is a nucleocytoplasmic shuttling protein with a possible role in mRNA processing
HAX-1 is a nucleocytoplasmic shuttling protein with a possible role in mRNA processing
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DOI：
10.1111/febs.12066
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发表时间：
2013-01-01
期刊：
影响因子：
5.4
通讯作者：
Siedlecki, Janusz A.
中科院分区：
文献类型：
--
作者：
Grzybowska, Ewa A.;Zayat, Valery;Siedlecki, Janusz A.
HAX-1是一种多功能蛋白，参与细胞凋亡、细胞运动和钙稳态的调节。据报道，它还与RNA结合：它与至少两个转录本的3‘非翻译区中的结构基序有关，但这种结合的功能意义尚不清楚。虽然HAX-1已在各种细胞室中被检测到，但它主要是细胞质的。我们对HAX-1异构体的详细定位研究揭示了部分核定位，其程度取决于蛋白质异构体。进一步的研究表明，HAX-1实际上是一种核质穿梭蛋白，依赖于Exportin 1核出口受体。系统的突变使HAX-1序列中的两个核输出信号得以识别。HAX-1核聚集是在被软霉素B抑制核输出后，也是在特定的细胞应激后。HAX-1的核定位和穿梭的生物学作用仍有待确定，但HAX-1的转录本结合特性表明，它可能与mRNA的加工和监控有关。在这项研究中，HAX-1状态被证明影响DNA聚合酶β的mRNA水平，DNA聚合酶β是HAX-1mRNA靶标之一，尽管这种影响只有在施加特定压力后才变得明显。此外，HAX-1与报告转录本的连接导致其表达显著下降。此外，HAX-1与P体标记物的共定位，在这里报道，暗示了在mRNA加工中的作用。这些结果表明，HAX-1可能参与了结合转录本的表达调控，可能是应激反应的一部分。结构化数字摘要HAX1和DCP1A，通过荧光显微镜共定位(视图相互作用：1，2)HAX1通过反标签免疫沉淀与XPO1物理相互作用(视图相互作用)
HAX-1 is a multi-functional protein that is involved in the regulation of apoptosis, cell motility and calcium homeostasis. It is also reported to bind RNA: it associates with structural motifs present in the 3' untranslated regions of at least two transcripts, but the functional significance of this binding remains unknown. Although HAX-1 has been detected in various cellular compartments, it is predominantly cytoplasmic. Our detailed localization studies of HAX-1 isoforms revealed partial nuclear localization, the extent of which depends on the protein isoform. Further studies demonstrated that HAX-1 is in fact a nucleocytoplasmic shuttling protein, dependent on the exportin 1 nuclear export receptor. Systematic mutagenesis allowed identification of the two nuclear export signals in the HAX-1 sequence. HAX-1 nuclear accumulation was observed after inhibition of nuclear export by leptomycin B, but also after specific cellular stress. The biological role of HAX-1 nuclear localization and shuttling remains to be established, but the HAX-1 transcript-binding properties suggest that it may be connected to mRNA processing and surveillance. In this study, HAX-1 status was shown to influence mRNA levels of DNA polymerase beta, one of the HAX-1 mRNA targets, although this effect becomes pronounced only after specific stress is applied. Moreover, HAX-1 tethering to the reporter transcript caused a significant decrease in its expression. Additionally, the HAX-1 co-localization with P-body markers, reported here, implies a role in mRNA processing. These results suggest that HAX-1 may be involved in the regulation of expression of bound transcripts, possibly as part of the stress response. Structured digital abstract HAX1 and DCP1A, colocalize by fluorescence microscopy (View Interaction: 1, 2) HAX1 physically interacts with XPO1 by anti tagcoimmunoprecipitation (View interaction)