Pinon-Lataillade Ghislaine, Masson Christel, Bernardino-Sgherri Jacqueline, Henriot Véronique, Mauffrey Philippe, Frobert Yveline, Araneda Silvia, Angulo Jaime F
Laboratoire de Génétique de la Radiosensibilité, CEA, Direction des Sciences du Vivant, Département de Radiobiologie et de Radiopathologie, B.P. 6, 92265 Fontenay aux Roses CEDEX, France.
J Cell Sci. 2004 Jul 15;117(Pt 16):3691-702. doi: 10.1242/jcs.01226.
Genotoxic agents deform DNA structure thus eliciting a complex genetic response allowing recovery and cell survival. The Kin17 gene is up-regulated during this response. This gene encodes a conserved nuclear protein that shares a DNA-binding domain with the bacterial RecA protein. The KIN17 protein binds DNA and displays enhanced expression levels in proliferating cultured cells, suggesting a role in nuclear metabolism. We investigated this by studying the expression profile of KIN17 protein during mouse spermatogenesis. As expected, the expression level of Kin17 is higher in proliferating than in differentiated cells. KIN17 is selectively extracted from this tissue by detergents and a fraction was tightly associated with the nuclear matrix. Germinal cells ubiquitously express Kin17 and the protein is located mainly in the nucleus except in elongated spermatids where cytoplasmic staining is also observed. Sertoli and germ cells that are no longer mitotically active express KIN17, suggesting a general role in all testicular cell types. In adult testis a significant proportion of KIN17 co-purifies with polyadenylated RNA. KIN17 directly binds RNA, preferentially poly(G) and poly(U) homopolymers. These results together with the identification of KIN17 as a component of the human spliceosome indicate that this protein may participate in RNA processing.
基因毒性剂会使DNA结构变形，从而引发复杂的基因反应，以实现恢复和细胞存活。Kin17基因在这种反应过程中上调。该基因编码一种保守的核蛋白，它与细菌RecA蛋白共享一个DNA结合结构域。KIN17蛋白结合DNA，并在增殖的培养细胞中显示出增强的表达水平，这表明它在核代谢中发挥作用。我们通过研究小鼠精子发生过程中KIN17蛋白的表达谱对此进行了研究。正如预期的那样，Kin17在增殖细胞中的表达水平高于分化细胞。去污剂可从该组织中选择性提取KIN17，并且有一部分与核基质紧密结合。生殖细胞普遍表达Kin17，该蛋白主要位于细胞核中，但在细长型精子细胞中也观察到细胞质染色。不再进行有丝分裂的支持细胞和生殖细胞表达KIN17，这表明它在所有睾丸细胞类型中都发挥着普遍作用。在成年睾丸中，相当一部分KIN17与聚腺苷酸化RNA共纯化。KIN17直接结合RNA，优先结合聚（G）和聚（U）同聚物。这些结果以及将KIN17鉴定为人剪接体的一个组成部分表明，该蛋白可能参与RNA加工。
