BOG pRb Binding Protein for Cell-cycle Control/transform

BOG（RBBP-9）是一种新的细胞蛋白，通过LXCXE基序与pRb、p107和p130相互作用。已产生纯合BOG-/-小鼠，并且在纯合动物中未发现可检测水平的BOG mRNA或蛋白。BOG-/-出生时健康，与BOG+/-和野生型动物相比以正常速率生长，并且具有生育能力。目前，我们正在对来自BOG-/-小鼠的大量苏木精和伊红染色组织进行组织学评价。我们已经开始使用从13.5天大的BOG -/-胚胎中分离的小鼠胚胎成纤维细胞（MEF），按照标准程序（3 T3和3 T9方案）并用于体外实验，以寻找BOG在细胞周期控制中的作用。初步结果表明，BOG-/- MEFs具有比野生型（WT）细胞更有限的增殖能力。-/-细胞比WT更早停止增殖，导致细胞总数缓慢但进行性减少。在高和低细胞密度条件下的结果是相同的。使用两个新的细胞系重复基于WST-1的增殖测定。结果表明，BOG-/- MEF的快速生长能力与基因型直接相关。将用增殖测定获得的数据结合在一起表明，BOG无效MEF表现出“早衰”表型。为了验证这一假设，我们选择衰老相关的β-半乳糖苷酶活性作为衰老标志物。结果与在BOG缺陷细胞中较早获得复制性衰老状态一致。

BOG (RBBP-9) is a novel cellular protein which interacts with pRb, p107 and p130 through the LXCXE motif. The homozygous BOG-/- mouse has been generated, and no detectible level of BOG mRNA nor protein was found in the homozygous animals. BOG-/- are born healthy, grow at a normal rate compared with BOG+/- and wildtype animals, and are fertile. At present we are performing histological evaluations of numerous haematoxylin and eosin stained tissues from BOG-/- mice. We have started to use mouse embryo fibroblasts (MEFs) isolated from 13.5 day old BOG -/- embryos in search of a role for BOG in cell cycle control, following standard procedures (3T3 and 3T9 protocols) and used for in vitro experiments. Preliminary results indicate that BOG-/- MEFs possess a more limited capacity to proliferate than the wildtype (WT) cells. The -/- cells stopped proliferating sooner than the WT resulting in a slow but progressive decrease in the total number of cells. The results were identical under both high and low cell density conditions. The WST-1 based proliferation assay was repeated using two new lines. The results confirm that the impared growth capacity of BOG-/- MEF is directly related to the genotype. Taking together the data obtained with the proliferation assays suggested that BOG null MEFs exhibited a "premature senescence" phenotype. To test that hypothesis, we chose the senescence associated b-galactosidase activity as a senescence marker. The results were consistent with an earlier acquisition of a replicative senescence status in the BOG deficient cells.