Function of placenta-specific transcription factor GCMa in the development of the placenta

GCMA/1是一种只在胎盘中表达的转录因子。它是合体母细胞发育所必需的。该因子的零突变会导致早期胚胎死亡。我们最初计划针对该蛋白提高特异性抗体。从大肠杆菌中表达和纯化hGCMa蛋白，制备多克隆抗体。1)抗体检测到hGCMa/1在大肠杆菌中表达。和昆虫细胞。Western blotting检测到正常足月胎盘组织中hGCMa/1和小鼠胎盘组织中mGCMa/1的表达。抗体在胎盘绒毛中检测到hGCMa1，其中检测到芳香酶和hCG a。这一结果进一步证实了我们之前的发现，hGCMa/1是这些基因表达所必需的(Yamada等人。J.Biol.Chem。1999274 32279-32286我们还试图获得针对该蛋白的鼠单抗。2)Western blotting检测到2个克隆，分别在大肠杆菌、昆虫细胞、正常足月胎盘和小鼠胎盘中检测到hGCMa/1。抗体的详细特征目前正在进行中。3)应用克隆技术检测GCMA/1在不同正常组织和肿瘤组织中的表达。GCMA/1的表达相当有限。在部分卵巢和胃标本中检测到低表达。有一例结肠癌标本显示出强表达。4)克隆了鸡GCM同源基因。新的GCM同源基因在发育中的卵子的胚外区域表达，表明其功能与哺乳动物的GCMA相似。

GCMa/1 is a transcription factor that solely expresses in the placenta. It is required for the development of syncytioblast. Null-mutation of the factor results early embryonic death due to the.We first planned to raise specific antibody for the protein. Polyclonal antibody was raised against hGCMa protein expressed and purified from E. coli. 1)The antibody detected hGCMa/1 expressed in E. coli. and insect cells. It detected authentic hGCMa/1 in normal term placenta and also mGCMa/1 in mouse placenta in Western blotting. The antibody detected hGCMa1 in chorionic villi of the placenta where aromatase and hCG a have been detected. The result further confirms our previous finding that hGCMa/1 is necessary for the expression of these genes (Yamada et al. J.Biol.Chem. 1999 274 32279-32286. We also tried to get mouse monoclonal antibodies against the protein. 2) We got 2 clones that detected hGCMa/1 in E. coli., insect cells, authentic hGCMa/1 in normal term placenta and also mGCMa/1 in mouse placenta in Western blotting. Detailed characterization of the antibodies are currently on-going. 3) We investigated the expression of GCMa/1 in various normal and tumor tissues using human Cancer Array (Clontec). GCMa/1 showed quite limited expression. Low expression was detected in some samples from ovary and stomach. There was one sample from colon cancer which showed strong expression. 4) We cloned a GCM orthologue from chicken. The new GCM ortholog expresses in the extra-embryonic region of developing egg, that suggest similar function to that of mammalian GCMa.