Lee V H, Schwoebel E, Prasad S, Cheung P, Timmons T M, Cook R, Dunbar B S
Department of Cell Biology, Baylor College of Medicine, Houston, Texas 77030.
J Biol Chem. 1993 Jun 15;268(17):12412-7.
A cDNA (rc75) encoding a 75-kDa rabbit zona pellucida (ZP) glycoprotein (R75) has been cloned and sequenced. The predicted amino acid sequence consists of 676 amino acids including seven potential N-glycosylation sites. The cDNA hybridizes to a 2.4-kilobase mRNA in ovary that is not detectable in other rabbit tissues. The R75 mRNA was also found to be expressed during the early stages of rabbit ovarian development (2-6 weeks of age) when the ovary contains primordial, primary, and early secondary follicles. The deduced amino acid sequence of rc75 has 77% similarity to the mouse ZP2 protein but no similarity to mouse ZP3. R75 also contains regions with 35-55% similarity to a previously cloned rabbit 55-kDa ZP protein. Monte Carlo simulation comparison confirmed that R75 has a significant probability of homology with mouse ZP2 and the rabbit 55-kDa ZP protein. Antibodies were developed against a fragment of R75 (rc75a cDNA) expressed in the pEX expression vector. These antibodies were used to confirm that the expressed protein contained epitopes found in the native rabbit ZP glycoprotein. These data suggest that some, but not all, ZP proteins may be conserved among different species and that within a species ZP proteins may share similar regions.
一个编码75千道尔顿兔透明带（ZP）糖蛋白（R75）的cDNA（rc75）已被克隆和测序。预测的氨基酸序列由676个氨基酸组成，包括7个潜在的N-糖基化位点。该cDNA与卵巢中一个2.4千碱基的mRNA杂交，而在其他兔组织中未检测到。还发现R75 mRNA在兔卵巢发育早期（2至6周龄）表达，此时卵巢含有原始卵泡、初级卵泡和早期次级卵泡。rc75推导的氨基酸序列与小鼠ZP2蛋白有77%的相似性，但与小鼠ZP3没有相似性。R75还包含与先前克隆的兔55千道尔顿ZP蛋白有35 - 55%相似性的区域。蒙特卡罗模拟比较证实，R75与小鼠ZP2和兔55千道尔顿ZP蛋白有显著的同源概率。针对在pEX表达载体中表达的R75片段（rc75a cDNA）制备了抗体。这些抗体用于确认表达的蛋白含有天然兔ZP糖蛋白中发现的表位。这些数据表明，不同物种之间部分（而非全部）ZP蛋白可能是保守的，并且在一个物种内ZP蛋白可能共享相似区域。
