CAJ | 학술논문

目的探讨G蛋白β和γ亚基在Gβγ与效应器相互作用中的地位，特别是γ亚基在此相互关系中的作用。方法利用酵母双杂交和自行构建的酵母三杂交系统分别研究Gβ1和Gβ1γ2与腺苷酸环化酶Ⅱ(ACⅡ)的相互作用。结果发现酵母三杂交系统中AD-β1，γ2和BD-ACⅡ间的相互作用明显强于双杂交系统中AD-β1和BD-ACⅡ的相互作用。对BD-ACⅡQ和AD-β1在酵母双杂交系统和三杂交系统中的表达进行免疫印迹杂交分析，发现其表达水平与β-半乳糖苷酶活力大小无关，即酵母三杂交系统和双杂交系统中相互作用的显著差别不是由BD-ACⅡQ和AD-β1蛋白表达水平的差异所造成。结论β亚基对维持Gβγ与ACⅡ的相互作用十分重要，而γ亚基的存在显著增强了β亚基与ACⅡ的相互作用，对维持Gβγ与ACⅡ的高亲和性很重要
목적탐토G단백β화γ아기재Gβγ여효응기상호작용중적지위，특별시γ아기재차상호관계중적작용。방법이용효모쌍잡교화자행구건적효모삼잡교계통분별연구Gβ1화Gβ1γ2여선감산배화매Ⅱ(ACⅡ)적상호작용。결과발현효모삼잡교계통중AD-β1，γ2화BD-ACⅡ간적상호작용명현강우쌍잡교계통중AD-β1화BD-ACⅡ적상호작용。대BD-ACⅡQ화AD-β1재효모쌍잡교계통화삼잡교계통중적표체진행면역인적잡교분석，발현기표체수평여β-반유당감매활력대소무관，즉효모삼잡교계통화쌍잡교계통중상호작용적현저차별불시유BD-ACⅡQ화AD-β1단백표체수평적차이소조성。결론β아기대유지Gβγ여ACⅡ적상호작용십분중요，이γ아기적존재현저증강료β아기여ACⅡ적상호작용，대유지Gβγ여ACⅡ적고친화성흔중요
To explore the individual roles of G protein β and γsubunit in the interactions with effectors. Methods We investigated the interactions of Gβ1 and Gβ1γ2 with adenylyl cyclase Ⅱ(ACⅡ) us ing the yeast two-hybrid and three-hybrid systems. Results When assayed for the abilities to activate the reporter gene, the interactions among AD-β1, γ2 and BD-AC ⅡQ in the three-hybrid system were more po tent than the interactions between AD-β1 and BD-AC ⅡQ in the two-hybrid system. The expressions of BD-AC ⅡQ and AD-β1 in transformants coexpressed AD-β1 and BD-AC ⅡQ, and transformants coexpressed AD-β1, γ2 and BD-AC ⅡQ were respectively detected. The comparisons between the reporter activity and the expression levels of BD-AC ⅡQ and AD-β1 in the yeast cells show there was no correlations, i.e.The difference in the reporter activity was not a reflection of differential expression level of the hybrid pro teins. Conclutions All these results suggest that G protein β1 subunit is sufficient to maintain the basic in teraction between Gβ1γ2 and AC ⅡQ, and γ2 subunit plays an important role in the high affinity interaction of Gβ1γ2 with ACⅡQ.