Iwahana Hiroyuki, Hayakawa Morisada, Kuroiwa Kenji, Tago Kenji, Yanagisawa Ken, Noji Sumihare, Tominaga Shin-ichi
Department of Biochemistry, Jichi Medical School, 3311-1 Yakushiji, Minamikawachi-machi, Kawachi-gun, Tochigi 329-0498, Japan.
Biochim Biophys Acta. 2004 Nov 24;1681(1):1-14. doi: 10.1016/j.bbaexp.2004.08.013.
The ST2 gene encodes receptor-like molecules that are very similar to the interleukin-1 receptors. Three types of ST2 gene products, ST2, ST2L, and ST2V, can be produced by alternative splicing. In the course of cloning the chicken ST2 and ST2L cDNAs, we identified a novel variant cDNA other than ST2, ST2L, or ST2V, and tentatively named it ST2LV. ST2LV was produced by alternative splicing that deleted the transmembrane domain of ST2L. The chicken ST2 gene consisted of 13 exons and had two promoters followed by noncoding exons 1a and 1b, like the ST2 genes of human, mouse, and rat. The chicken ST2 mRNA was detected by RT-PCR as early as embryonic day 5. After that, the chicken ST2 mRNA was expressed in all examined organs, including the brain, eye, heart, lung, and liver. The chicken ST2LV mRNA was detected from embryonic day 10. The chicken ST2LV cDNA was transiently expressed in COS-7 cells. A protein of 69 kDa was detected in the culture supernatant, and the size of the protein was reduced to 53 kDa by treatment with peptide-N-glycosidase F, which suggested that ST2LV is a new soluble secreted and N-glycosylated variant of the ST2 gene product.
ST2基因编码与白细胞介素-1受体非常相似的受体样分子。通过可变剪接可产生三种类型的ST2基因产物，即ST2、ST2L和ST2V。在克隆鸡ST2和ST2L cDNA的过程中，我们鉴定出一种不同于ST2、ST2L或ST2V的新型可变剪接cDNA，并暂时将其命名为ST2LV。ST2LV是通过删除ST2L跨膜结构域的可变剪接产生的。鸡ST2基因由13个外显子组成，与人类、小鼠和大鼠的ST2基因一样，有两个启动子，后面跟着非编码外显子1a和1b。早在胚胎第5天通过RT-PCR就检测到了鸡ST2 mRNA。此后，鸡ST2 mRNA在所有检测的器官中表达，包括脑、眼、心脏、肺和肝脏。从胚胎第10天开始检测到鸡ST2LV mRNA。鸡ST2LV cDNA在COS-7细胞中瞬时表达。在培养上清液中检测到一种69 kDa的蛋白质，用肽-N-糖苷酶F处理后，该蛋白质的大小降至53 kDa，这表明ST2LV是ST2基因产物的一种新的可溶性分泌型且N-糖基化的变体。
