DNG1, a Dictyostelium homologue of tumor suppressor ING1 regulates differentiation of Dictyostelium cells

dng1 is a Dictyostelium homologue of the mammalian tumor suppressor ING gene. DNG1 protein localizes in the nucleus, and has a highly conserved PHD finger domain found in chromatin-remodeling proteins. Both dng1 disruption and overexpression impaired cell proliferation. In dng1-null cells, the progression of differentiation was delayed in a cell-density-dependent manner, and many tiny aggregates were formed. Exogenously applied cAMP pulses reversed the inhibitory effect caused by dng1 disruption on the aggregation during early development, but formation of tiny aggregates was not restored. dng1-overexpressing cells acquired the ability to undergo chemotaxis to cAMP earlier and exhibited enhanced differentiation. These phenotypes were found to be coupled with altered expressions of early genes such as cAMP receptor 1 (car1) and contact site A (csA). Furthermore, disordered histone modifications were demonstrated in dng1-null cells. These results suggest a regulatory role of dng1 in the transition of cells from growth to differentiation.Received 29 December 2004; received after revision 24 May 2005; accepted 26 May 2005     

蛋白质的磷酸化修饰及其研究方法

蛋白质磷酸化是一种重要的翻译后修饰,它参与和调控生物体内的许多生命活动。随着蛋白质组技术的不断发展,蛋白质磷酸化的研究越来越受到广泛的重视。本文介绍了蛋白质磷酸化修饰的主要类型与功能、磷酸化兰白质及磷酸化肽的标记和分离与富集、磷酸化肽及磷酸化位点分析以及蛋白质的磷酸化改性等方法,并综述了近年来国内外的主要研究进展。     

组蛋白修饰与癫痫的发生发展研究进展

癫痫是由脑部神经元异常同步或过度放电导致的一种慢性脑部疾病。在神经系统疾病中，癫痫已成为仅次于脑血管病的第二大严重威胁人类健康的疾病，且其发病机制至今未明。表观遗传机制是调节基因表达的一种方式，其中组蛋白修饰是主要的表观遗传修饰之一。组蛋白修饰的异常与癫痫的发生发展密切相关，本文对组蛋白修饰与癫痫的关系进行综述，以期从组蛋白修饰的角度阐明两者之间的关系，为癫痫的防治提供新思路。