Raho G, Barone V, Rossi D, Philipson L, Sorrentino V
DIBIT, Istituto Scientifico San Raffaele, Milan, Italy.
Gene. 2000 Oct 3;256(1-2):13-7. doi: 10.1016/s0378-1119(00)00363-2.
The murine gas5 gene was originally isolated based on its preferential expression in the growth arrest phase of the cell cycle. This gene contains 12 exons from which two alternatively spliced transcripts have been initially identified. More recently, it has been reported that both human and murine gas5 genes contain in their introns sequences homologous to the small nucleolar RNAs involved in the processing of ribosomal RNA. Here we report on the identification and analysis of the expression pattern of two novel alternatively spliced mouse gas5 mRNAs which contain no obvious open reading frame (ORF). Using antibodies generated against the putative amino acid sequence deduced from the gas5 cDNAs, we were not able to detect any Gas5 protein in cultured cells or murine tissues extracts. Even more definitive evidence that the gas5 gene may not encode a protein was obtained by cloning and sequencing the rat gas5 gene which revealed that the putative ORF is interrupted by a stop codon after the first 13 amino acids.
小鼠gas5基因最初是根据其在细胞周期生长停滞期的优先表达而分离出来的。该基因包含12个外显子，最初已鉴定出两种可变剪接转录本。最近，有报道称，人类和小鼠的gas5基因在其内含子序列中都含有与参与核糖体RNA加工的小核仁RNA同源的序列。在这里，我们报告了两种新型可变剪接的小鼠gas5 mRNA的鉴定和表达模式分析，它们没有明显的开放阅读框（ORF）。使用针对从gas5 cDNA推导的假定氨基酸序列产生的抗体，我们无法在培养细胞或小鼠组织提取物中检测到任何Gas5蛋白。通过克隆和测序大鼠gas5基因获得了更确凿的证据，表明gas5基因可能不编码蛋白质，该基因显示假定的ORF在最初的13个氨基酸后被一个终止密码子中断。
