Robakis N K, Sawh P R, Wolfe G C, Rubenstein R, Carp R I, Innis M A
Proc Natl Acad Sci U S A. 1986 Sep;83(17):6377-81. doi: 10.1073/pnas.83.17.6377.
We have isolated a hamster cDNA clone representing the coding sequences for the entire precursor of prion protein (PrP) 27-30. This clone encodes a protein of 254 residues and contains an in-frame ATG codon 42 bases upstream from the one previously reported. Analysis of the predicted amino acid sequence suggests that the PrP precursor protein contains an amino-terminal signal sequence, and a membrane-spanning domain in the carboxyl terminus. Cleavage of the signal peptide would produce a mature protein of 232 amino acids. Sequences homologous to the hamster PrP cDNA were detected in hamster, mouse, sheep, human, and rabbit genomes. A related 2.5-kilobase transcript was present in the brain of normal and scrapie-infected rodents. Two homologous transcripts, 2.5 and 1.1 kilobases, were detected in the lung and heart of normal animals. No PrP mRNA was detected in spleen stroma, a tissue known to contain high titers of scrapie. Antisera raised to the 27- to 30-kDa polypeptide detected the PrP in both normal and infected brains but failed to detect this protein in either normal or infected spleens. Homologous mRNA species were detected in human, sheep, and rabbit brain, even though the latter is resistant to scrapie infection. Our data suggest that PrP is not a necessary component of the infectious agent.
我们分离出了一个仓鼠cDNA克隆，它代表朊病毒蛋白（PrP）27 - 30整个前体的编码序列。该克隆编码一个含254个残基的蛋白质，并且在先前报道的起始密码子上游42个碱基处含有一个符合读框的ATG密码子。对预测的氨基酸序列分析表明，PrP前体蛋白含有一个氨基末端信号序列以及羧基末端的一个跨膜结构域。信号肽的切割将产生一个含232个氨基酸的成熟蛋白。在仓鼠、小鼠、绵羊、人类和兔子的基因组中检测到了与仓鼠PrP cDNA同源的序列。在正常和感染羊瘙痒病的啮齿动物大脑中存在一个相关的2.5千碱基转录本。在正常动物的肺和心脏中检测到了两个同源转录本，分别为2.5千碱基和1.1千碱基。在脾基质中未检测到PrP mRNA，脾基质是已知含有高滴度羊瘙痒病病原体的组织。针对27至30 kDa多肽产生的抗血清在正常和感染的大脑中都检测到了PrP，但在正常或感染的脾脏中均未检测到该蛋白。在人类、绵羊和兔子的大脑中检测到了同源mRNA种类，尽管兔子对羊瘙痒病感染具有抗性。我们的数据表明PrP不是感染因子的必要组成部分。
