Campomenosi Paola, Salis Silvia, Lindqvist Christer, Mariani Davide, Nordström Tommy, Acquati Francesco, Taramelli Roberto
Department of Biotechnology and Molecular Sciences, University of Insubria, Via JH Dunant, 3, 21100 Varese, Italy.
Arch Biochem Biophys. 2006 May 15;449(1-2):17-26. doi: 10.1016/j.abb.2006.02.022. Epub 2006 Mar 13.
Ribonucleases are ubiquitous enzymes involved in RNA metabolism and are classified in several families on the basis of their structural, catalytic, and biological properties. Here, we describe characterization of the only human member of the Rh/T2/S family of acid hydrolases so far described, named RNASET2. This protein was previously reported to have an interesting biological function in the control of tumourigenesis and metastatization. We show that RNASET2 is present in multiple forms in human cell lines and mouse tissues, one of which represents the full length, glycosylated and secreted form, while the others are proteolytic products. RNASET2 is endowed with catalytic activity as demonstrated with purified recombinant protein expressed in the Baculovirus Expression Vector System and in a human cell line ectopically expressing various types of constructs. Furthermore, we document for this protein a lysosomal localization as described for other members of the Rh/T2/S family of ribonucleases. The results presented herein represent a further advancement toward the molecular understanding of the tumour suppressive properties of the human RNASET2 protein.
核糖核酸酶是参与RNA代谢的普遍存在的酶，根据其结构、催化和生物学特性可分为几个家族。在此，我们描述了迄今为止所描述的Rh/T2/S酸性水解酶家族中唯一的人类成员RNASET2的特性。该蛋白先前被报道在肿瘤发生和转移控制中具有有趣的生物学功能。我们表明，RNASET2在人类细胞系和小鼠组织中以多种形式存在，其中一种代表全长、糖基化和分泌形式，而其他的则是蛋白水解产物。如在杆状病毒表达载体系统中表达的纯化重组蛋白以及在异位表达各种类型构建体的人类细胞系中所证明的，RNASET2具有催化活性。此外，正如核糖核酸酶Rh/T2/S家族的其他成员一样，我们证明该蛋白定位于溶酶体。本文呈现的结果代表了在分子层面理解人类RNASET2蛋白肿瘤抑制特性方面的进一步进展。
