小鼠基质重塑相关7(MXRA7)基因产物在肝内互作蛋白质的鉴定（英文）

Identification of Potential Partners of Matrix-Remodeling Associated 7( MXRA7) in Murine Liver

基质重塑相关7(matrix remodeling associated 7,MXRA7)基因于2002年被命名,但无论在人类或其他动物体系,该基因或其蛋白质产物的功能均未知。直至我们最近的研究表明,该基因可能参与眼睛发育或肝损伤及修复。在本研究中,应用酵母双杂交策略,用小鼠MXRA7诱饵载体对小鼠肝cDNA文库进行筛选,发现23种蛋白质(MUP1, Cpt1a, Mat1a, aldh1l1, Cytb, H2-K1, Psmb1, marc2, Atp5j2, Sec24D, Trf, Rdh7, Apoe, Glud1, Gmfb, Alb, Hdlbp, Pzp, Etnk2, Nrn1, Serpina1a, Apoa2, GNMT)可能直接或间接地与MXRA7蛋白发生相互作用。其中,主要尿蛋白1(major urinary protein,MUP1)或其同家族蛋白质占所有候选克隆的1/6,提示其很可能是小鼠肝内与MXRA7蛋白有较强相互作用的蛋白质。通过基因重组在Hepa 1-6肝癌细胞系中同时过表达MXRA7和MUP1蛋白,荧光染色证明这两种蛋白质在细胞内共定位,应用抗MXRA7或MUP1的抗体进行Pull-down检测,则证明二者共同存在于细胞裂解液中。另外,重组MXRA7蛋白和MUP1蛋白在无任何其他蛋白质的缓冲液体系中直接形成复合体。因此,至少在小鼠肝组织体系中,MXRA7蛋白可能通过与MUP1等蛋白质的相互作用而发挥作用。

The functions of matrix-remodeling associated 7( MXRA7) gene or its protein products remained largely unknown at all levels in either human or other animals,until recent studies revealed involvement of this gene in eye development or liver disease models. In this paper,we described that yeast-two-hybrid screening on MXRA7 with a murine liver cDNA library disclosed 23 proteins( MUP1,Cpt1 a,Mat1a,aldh1l1,Cytb,H2-K1,Psmb1,marc2,Atp5j2,Sec24 D,Trf,Rdh7,Apoe,Glud1,Gmfb,Alb,Hdlbp,Pzp,Etnk2,Nrn1,Serpina1 a,Apoa2 and GNMT) that probably interact with MXRA7 proteins directly or indirectly. Among them,MUP1 or others in the same family,accounted for one sixth of all candidate clones. Therefore,MUP1 was the most possible partner of MXRA7 proteins.When a murine hepatoma cell line was transfected to overexpress MXRA7 and MUP1 simultaneously,immunofluorescence and pull-down assay indicated that these two proteins co-localized in the cells or coexisted in the same complexes in cell lysates. Furthermore,recombinant MXRA7 proteins and MUP1 can form complexes directly in absence of any other proteins. In conclusion,MXRA7 proteins in murine livers might interact with metabolism-related proteins such as MUP1 etc,through which involved in metabolisms in liver.