Piñol-Roma S, Dreyfuss G
Howard Hughes Medical Institute and Department of Biochemistry and Biophysics, University of Pennsylvania School of Medicine, Clinical Research Building, Room 328, 422 Curie Boulevard, Philadelphia, PA 19104-6148, USA.
Trends Cell Biol. 1993 May;3(5):151-5. doi: 10.1016/0962-8924(93)90135-n.
The proteins of heterogeneous nuclear ribonucleoprotein (hnRNP) complexes are among the most abundant proteins in the nucleus. They bind nascent pre-mRNAs and remain associated with them through their nuclear processing into mRNA. Recent findings indicate roles for hnRNP proteins in the biogenesis of mRNA and reveal a surprising intracellular localization pathway for these proteins. Several of the hnRNP proteins shuttle continuously between the nucleus and the cytoplasm, and the reaccumulation of the exported hnRNP proteins in the nucleus occurs by a novel process that is dependent on transcription by RNA polymerase II. These findings suggest possible novel functions for hnRNP proteins in the cytoplasm and in the nucleocytoplasmic transport of mRNA.
异质性细胞核核糖核蛋白（hnRNP）复合物中的蛋白质是细胞核中最丰富的蛋白质之一。它们结合新生的前体mRNA，并在其加工成mRNA的核过程中一直与其结合。最近的研究结果表明hnRNP蛋白在mRNA生物合成中发挥作用，并揭示了这些蛋白质一条令人惊讶的细胞内定位途径。几种hnRNP蛋白在细胞核和细胞质之间持续穿梭，并且输出到细胞核外的hnRNP蛋白在细胞核中的重新积累是通过一种依赖于RNA聚合酶II转录的新过程发生的。这些发现提示了hnRNP蛋白在细胞质以及mRNA的核质运输中可能具有新功能。
