Lodge A P, Walsh A, McNamee C J, Moss D J
Department of Human Anatomy and Cell Biology, University of Liverpool, New Medical School, UK.
Eur J Biochem. 1999 Apr;261(1):137-47. doi: 10.1046/j.1432-1327.1999.00246.x.
In a screen for myosin-like proteins in embryonic chicken brain, we have identified a novel nuclear protein structurally related to hnRNP-U (heterogeneous nuclear ribonuclear protein U). We have called this protein chURP, for chicken U-related protein. In this screen, chURP was immunoreactive with two myosin antibodies and, in common with the unconventional myosins, bound calmodulin in vitro in both the presence and absence of calcium ions. Determination of 757 amino acids of the chURP sequence revealed that it shares 41% amino acid identity with human and rat hnRNP-U, although chURP and hnRNP-U appear not to be orthologous proteins. ChURP is ubiquitously expressed in the nuclei of all chick tissues and, as one of a growing number of calmodulin-binding proteins to be identified in the nucleus, further highlights the potential of calmodulin as a regulator of nuclear metabolism.
在对鸡胚脑中类肌球蛋白蛋白的筛选过程中，我们鉴定出一种与hnRNP-U（不均一核核糖核蛋白U）结构相关的新型核蛋白。我们将此蛋白称为chURP，即鸡U相关蛋白。在此筛选中，chURP与两种肌球蛋白抗体发生免疫反应，并且与非常规肌球蛋白一样，在有钙离子和无钙离子的情况下均能在体外结合钙调蛋白。对chURP序列757个氨基酸的测定表明，它与人和大鼠的hnRNP-U有41%的氨基酸同一性，尽管chURP和hnRNP-U似乎并非直系同源蛋白。ChURP在所有鸡组织的细胞核中普遍表达，作为在细胞核中不断被鉴定出的越来越多的钙调蛋白结合蛋白之一，进一步凸显了钙调蛋白作为核代谢调节剂的潜力。
