Van den Broeck D, Van der Straeten D, Van Montagu M, Caplan A
Laboratorium voor Genetica, Universiteit Gent, Belgium.
Plant Physiol. 1994 Oct;106(2):559-66. doi: 10.1104/pp.106.2.559.
Biologically relevant concentrations as low as 500 microM spermine led to the specific release of chromatin-associated proteins from nuclei of rice (Oryza sativa) seedlings. Using a southwestern technique, it was shown that several of these proteins bind DNA. This affinity was lost upon in organello phosphorylation by an endogenous kinase. The effect of spermine was very specific. Spermidine was far less effective and putrescine was essentially ineffective in releasing these proteins. The most abundant spermine-released protein was shown to be homologous to the maize HMG1 protein. Our results suggest that spermine induces the release of spermine-released proteins by changing DNA conformation. Binding of these proteins might be sensitive to long-range changes in chromosome structure caused by torsional stress.
低至500微摩尔的生物相关浓度的精胺会导致水稻（Oryza sativa）幼苗细胞核中与染色质相关的蛋白质特异性释放。使用蛋白质印迹杂交技术表明，这些蛋白质中有几种能结合DNA。这种亲和力在内源激酶进行的细胞器内磷酸化后丧失。精胺的作用非常特异。亚精胺的效果要差得多，而腐胺在释放这些蛋白质方面基本无效。已证明释放量最大的精胺释放蛋白与玉米HMG1蛋白同源。我们的结果表明，精胺通过改变DNA构象诱导精胺释放蛋白的释放。这些蛋白质的结合可能对由扭转应力引起的染色体结构的长程变化敏感。
