Honoré B, Madsen P, Rasmussen H H, Vandekerckhove J, Celis J E, Leffers H
Institute of Medical Biochemistry, Danish Centre for Human Genome Research, Aarhus University.
Gene. 1993 Dec 8;134(2):283-7. doi: 10.1016/0378-1119(93)90108-f.
We have cloned and expressed a cDNA encoding the 32-kDa subunit (P32) of the human pre-mRNA splicing factor, SF2. This cDNA extends beyond the 5'-end of a previously reported cDNA [Krainer et al., Cell 66 (1991) 383-394]. Importantly, our fragment includes an ATG start codon which was absent from the previously reported cDNA, where it was suggested that translation might initiate at a CTG codon instead of at an ATG codon. Using the vaccinia virus (Vv) expression system, we demonstrate that translation starts at the conventional ATG start codon and not at the CTG codon. The protein is synthesized as a pro-protein of 282 amino acids (aa) that is post-translationally processed by removal of the initial 73 aa to a mature protein of 209 aa.
我们克隆并表达了一个编码人前体mRNA剪接因子SF2的32 kDa亚基（P32）的cDNA。这个cDNA延伸到了先前报道的cDNA的5'端之外[Krainer等人，《细胞》66（1991）383 - 394]。重要的是，我们的片段包含一个ATG起始密码子，而先前报道的cDNA中没有该密码子，之前有人认为翻译可能起始于CTG密码子而非ATG密码子。利用痘苗病毒（Vv）表达系统，我们证明翻译起始于常规的ATG起始密码子而非CTG密码子。该蛋白质最初作为一个282个氨基酸（aa）的前体蛋白合成，通过去除最初的73个aa进行翻译后加工，成为一个209个aa的成熟蛋白。
