Sureau A, Soret J, Guyon C, Gaillard C, Dumon S, Keller M, Crisanti P, Perbal B
Laboratoire d'Oncologie Virale et Moléculaire, Unité de Formation et de Recherche de Biochimie, Université Paris 7 (D. Diderot), 2 Place Jussieu, 75005 Paris, France.
Nucleic Acids Res. 1997 Nov 15;25(22):4513-22. doi: 10.1093/nar/25.22.4513.
The PR264/SC35 splicing factor belongs to the family of SR proteins which function as essential and alternative splicing factors. Here, we report that the human PR264/SC35 locus is bidirectionally transcribed. Double in situ hybridization experiments have allowed simultaneous detection of sense and antisense RNA in human CCRF-CEM cells, suggesting that expression of the corresponding genes is not mutually exclusive. We have characterized three main classes of ET RNAs encoded by the opposite strand of the PR264/SC35 gene and containing PR264/SC35-overlapping sequences, PR264/SC35-non overlapping sequences or a combination of both. We show that their expression results from the use of alternative promoters, exons and polyadenylation signals. PR264/SC35-non overlapping ET mRNA species potentially encode two protein isoforms (449 and 397 amino acids) and are expressed from the PR264/SC35 promoting region. Northern blots and RNase protection analyses indicate that ET polyadenylated RNAs are differentially expressed in several human cell lines. Similar studies performed in the mouse have revealed that the bidirectional transcription of the PR264/SC35 locus is a conserved mechanism and that the open reading frame identified in a subset of human ET mRNAs is highly conserved (93% homology). Northern blot analyses performed with several murine tissues confirmed the differential expression of the ET gene and revealed that it is predominantly expressed in the testis.
PR264/SC35剪接因子属于SR蛋白家族，该家族蛋白作为必需剪接因子和可变剪接因子发挥作用。在此，我们报道人类PR264/SC35基因座是双向转录的。双重原位杂交实验能够同时检测人类CCRF-CEM细胞中的正义RNA和反义RNA，这表明相应基因的表达并非相互排斥。我们已经鉴定出由PR264/SC35基因的反义链编码的三类主要的ET RNA，它们包含与PR264/SC35重叠的序列、不与PR264/SC35重叠的序列或两者的组合。我们表明它们的表达源于使用可变启动子、外显子和聚腺苷酸化信号。不与PR264/SC35重叠的ET mRNA种类可能编码两种蛋白质异构体（分别含449和397个氨基酸），并从PR264/SC35启动子区域表达。Northern印迹和核糖核酸酶保护分析表明，ET聚腺苷酸化RNA在几种人类细胞系中差异表达。在小鼠中进行的类似研究表明，PR264/SC35基因座的双向转录是一种保守机制，并且在一部分人类ET mRNA中鉴定出的开放阅读框高度保守（同源性为93%）。对几种小鼠组织进行的Northern印迹分析证实了ET基因的差异表达，并表明它主要在睾丸中表达。
