【摘要】：激活素作為TGF-β超家族的細(xì)胞增殖、分化因子,其作用的多面性和組織學(xué)特異性,與激活素作用的細(xì)胞內(nèi)信號(hào)傳導(dǎo)差異有關(guān)。在激活素信號(hào)傳導(dǎo)中,激活素受體相互作用蛋白(Activin receptor-interacting protein,ActRIP)是一組新發(fā)現(xiàn)的信號(hào)傳導(dǎo)蛋白。本研究在克隆新的ActRIP家族蛋白——ActRIP2a基因基礎(chǔ)上,進(jìn)一步比較研究ActRIP2a與ActRIP1-3組織分布、細(xì)胞內(nèi)表達(dá)格局以及生物學(xué)活性的差異。 本研究克隆了新的激活素受體相互作用蛋白2a(ActRIP2a)全編碼基因,cDNA全長(zhǎng)1008bp,編碼153個(gè)氨基酸殘基,與ActRIP2僅在編碼區(qū)第15和99位氨基酸不同,ActRIP2a的PDZ功能區(qū)與ActRIP1的蛋白結(jié)合功能區(qū)PDZ5存在33%同源性,與ActRIP3的ActR Ⅱ結(jié)合功能區(qū)具有96%同源性,但與ActRIP3的C末端無同源性。哺乳細(xì)胞雙雜交系統(tǒng)證實(shí)ActRIP2a可與ActR ⅡA相互作用,免疫沉淀實(shí)驗(yàn)進(jìn)一步證實(shí)ActRIP2a可與ActR ⅡA穩(wěn)定結(jié)合,Pull-down實(shí)驗(yàn)結(jié)果表明ActRIP2a通過其N末端PDZ樣功能區(qū)與天然ActR ⅡA相互作用,免疫沉淀實(shí)驗(yàn)表明ActRIP2a可以形成同源雙聚體蛋白,但與ActRIP2不能構(gòu)成異源雙聚體。 Northern雜交顯示ActRIP1、2、3 mRNA表達(dá)存在組織學(xué)分布上的差異,RT-PCR檢測(cè)結(jié)果顯示,ActRIP2a mRNA在大腦組織、垂體、睪丸中表達(dá)較高,胰腺、卵巢組織中表達(dá)較弱,而在其它組織中未見明顯表達(dá);ActRIP1 mRNA在腦干、大腦、小腦、垂體、下丘腦、睪丸、腎上腺組織中有表達(dá),其他組織內(nèi)未見表達(dá);而sActRIP1(short ActRIP1)在心肌及脾臟組織內(nèi)未見表達(dá),其他組織均有不同程度表達(dá)。ActRIP2及ActRIP3則在多種組織內(nèi)均有表達(dá)。免疫組織化學(xué)染色結(jié)果也顯示,ActRIP2在小鼠各組織幾乎均有著色;ActRIP1在肺、胰腺及睪丸的曲精細(xì)管內(nèi)幾乎沒有染色反應(yīng),而在其他組織有不同程度著色;小鼠腦
[Abstract]:Activin, as a cell proliferation and differentiation factor of TGF- 尾 superfamily, has many facets and histological specificity, which is related to the difference of intracellular signal transduction induced by activin. Activin receptor interaction protein (Activin receptor-interacting protein,ActRIP) is a newly discovered signal transduction protein in activin signal transduction. On the basis of cloning ActRIP2a gene, a new ActRIP family protein, the differences of tissue distribution, intracellular expression pattern and biological activity between ActRIP2a and ActRIP1-3 were further studied. In this study, a novel activin receptor interaction protein 2a (ActRIP2a) gene was cloned. The total length of cDNA is 1008bpand encodes 153 amino acid residues, which is different from that of ActRIP2 only at the 15th and 99th amino acids in the coding region. There was 33% homology between PDZ domain of ActRIP2a and PDZ5 of ActRIP1 protein binding domain, 96% homology with ActR 鈪，

本文編號(hào)：2420325