來(lái)自中山大學(xué)附屬第二醫(yī)院的研究人員以多種實(shí)驗(yàn)方法，研究工具為基礎(chǔ),，發(fā)現(xiàn)了重要轉(zhuǎn)錄因子Sox9的一個(gè)分子機(jī)制,，這對(duì)于研究骨形成具有重要意義。這一研究成果公布在Biochem Biophys Res Commun.上,。
在這篇最新的文章中,，研究人員圍繞著Sox9展開(kāi)了研究，利用各種研究手段發(fā)現(xiàn)了之前未知的一種分子機(jī)制,。
Sox9是軟骨形成（chondrogenesis）過(guò)程中一個(gè)十分關(guān)鍵的轉(zhuǎn)錄因子,，雖然已經(jīng)有研究表明骨形成蛋白2(bone morphogenetic protein 2,BMP2)能誘導(dǎo)Sox9的表達(dá)，但是其中的機(jī)制至今并不清楚,。
研究人員利用體內(nèi)實(shí)驗(yàn)的方法對(duì)BMP2誘導(dǎo)的Sox9關(guān)鍵啟動(dòng)子周圍的染色體組織的變化進(jìn)行了分析,，通過(guò)BMP2誘導(dǎo)后核酸酶超敏位點(diǎn)圖譜，研究人員發(fā)現(xiàn)Sox9近側(cè)啟動(dòng)子存在一個(gè)誘導(dǎo)性的超敏位點(diǎn),，而免疫共沉實(shí)驗(yàn)則證明BMP2能增加轉(zhuǎn)錄因子NF－Y與組蛋白去甲基轉(zhuǎn)移酶p300/CBP的關(guān)聯(lián),。并且研究人員還發(fā)現(xiàn)BMP2誘導(dǎo)能引起Sox9基因處的組蛋白乙酰化和甲醇化。
這些研究結(jié)果表明Sox9基因由BMP2誘導(dǎo)的轉(zhuǎn)錄活性與染色體和組蛋白的變化有關(guān),。（生物谷Bioon.com）
相關(guān)介紹：染色質(zhì)免疫沉淀法（Chromatin immunoprecitation,，ChIP）是研究體內(nèi)DNA與蛋白質(zhì)相互作用的重要工具。它可以靈敏地檢測(cè)目標(biāo)蛋白與特異DNA片段的結(jié)合情況,，還可以用來(lái)研究組蛋白與基因表達(dá)的關(guān)系,。核小體組蛋白可以發(fā)生多種翻譯后的共價(jià)修飾，如乙?；?、甲基化、磷酸化,、泛素化等,，這些共價(jià)修飾與真核基因的表達(dá)密切相關(guān)。根據(jù)“組蛋白密碼”假說(shuō),，組蛋白的各種共價(jià)修飾的組合會(huì)以協(xié)同或拮抗的方式誘導(dǎo)特異的下游生物學(xué)功能,，因此，ChIP也為研究組蛋白修飾在基因表達(dá)中的作用,，全面闡明真核基因的表達(dá)調(diào)控機(jī)制提供了強(qiáng)有力的研究工具。
中國(guó)第一ChIP論壇：ChIP Forum
生物谷推薦原始出處：
Biochemical and Biophysical Research Communications doi:10.1016/j.bbrc.2008.12.062
Bone Morphogenetic Protein-2 induces chromatin remodeling and modification at the proximal promoter of Sox9 gene
Qiuhui Pana, Yanfeng Wua, Tianxin Lina, Herui Yaob, Zhonghan Yange, Guoquan Gaoe, Erwei Songc, , and Huiyong Shend, ,
aMedical Research Center, No. 2 Affiliated Hospital, Sun Yat-sen University, Guangzhou 510120, PR China
bDepartment of Cancer, No. 2 Affiliated Hospital, Sun Yat-sen University, Guangzhou 510120, PR China
cDepartment of Breast Surgery, No. 2 Affiliated Hospital, Sun Yat-sen University, Guangzhou 510120, PR China
dDepartment of Orthopedics, No. 2 Affiliated Hospital, Sun Yat-sen University, Guangzhou 510120, PR China
eDepartment of Biochemistry, Zhongshan Medical School, Sun Yat-sen University, Guangzhou 510080, PR China
Abstract
Sox9 is a key transcription factor which plays an important role in chondrogenesis. Although Bone Morphogenetic Protein-2 (BMP-2) has been reported to induce Sox9 expression, the underlying molecular mechanism remains elusive. Here, we used in vivo approaches to characterize BMP-2-induced alterations in chromatin organization around the Sox9 core promoter. Nuclease hypersensitive site mapping following BMP-2 stimulation showed an inducible hypersensitive site in the Sox9 proximal promoter. Immunoprecipitation (IP) experiments demonstrated that BMP-2 increased the association of the transcription factor NF-Y with histone acetyltransferase p300/CBP. Chromatin immunoprecipitation (ChIP) analysis showed the binding of the NF-Y–p300 complex to the Sox9 gene proximal promoter along with PCAF and RNA polymerase II. We also found that BMP-2 stimulation caused histone hyperacetylation and methylation at the Sox9 gene. Collectively, these data suggest that the activation of Sox9 gene transcription by BMP-2 is associated with chromatin remodeling and histone modification.
