胎盤融合性蛋白質 syncytin 2 的功能探討

Abstract

Data mining of the human genome sequence has revealed two human endogenous retrovirus (HERV) envelope proteins: one is HERV-W, also called syncytin and the other is HERV-FRD named syncytin2. These two genes appear to be almost exclusively expressed in placenta, in particular, in trophoblasts that are the specialized cells of the placenta playing a major role in implantation and formation of the maternal-fetal interface. In the current study, we characterize the fusogenic function of syncytin2. First, we induced syncytin2 antibody and then using this antibody and syncytin antibody to screen pre-eclamptic placenta and gestation age-matched controls. We found that the protein level of syncytin and syncytin2 in pre-eclampsia patient is decreased compared with the controls. We further performed domain swapping analysis and constructed chimeric protein, SU1-TM2. We found that both SU1-TM2 can be processing into SU and TM domains. On the observation of fusion assay, chimeric protein, SU1-TM2, can not mediated cell-cell fusion and propose that SU1-TM2 lost some kinds of interaction between. SU and TM domains We also studied cell fusion in three placental cell lines, BeWo, JEG3, and JAR. BeWo and JEG3 cells underwent spontaneous cell fusion, but not JAR cells. We investigated the possible mechanisms underlying the loss of spontaneous cell fusion in JAR. We ruled out the possibilities of furin processing and receptor deficiency in JAR cells and proposed that mutation in syncytin and syncytin2 genes in JAR cell line is a possible reason attributed to the loss of spontaneous cell fusion.