Functional analysis of the Interleukin-1 Receptor-Related ST2 Gene Products

Research Project

Project/Area Number	09680628
Research Category	Grant-in-Aid for Scientific Research (C)
Allocation Type	Single-year Grants
Section	一般
Research Field	Functional biochemistry
Research Institution	Jichi Medical School
Principal Investigator	IWAHANA Hiroyuki Jichi Medical School, Faculty of Medicine Lecture, 医学部, 講師 (80291623)
Co-Investigator(Kenkyū-buntansha)	小坂明子自治医科大学, 医学部, 助手 (10281297) YANAGISAWA Ken Jichi Medical School, Faculty of Medicine Lecture, 医学部, 助教授 (50182366)
Project Period (FY)	1997 – 1998
Project Status	Completed (Fiscal Year 1998)
Budget Amount *help	¥2,800,000 (Direct Cost: ¥2,800,000) Fiscal Year 1998: ¥1,100,000 (Direct Cost: ¥1,100,000) Fiscal Year 1997: ¥1,700,000 (Direct Cost: ¥1,700,000)
Keywords	ST2 / ST2L / IL-1 receptor family / promoter / モノクローナル抗体 / 細胞増殖
Research Abstract	Two distinct types of the ST2 gene products, ST2, a soluble secreted form, and ST2L, a transmembrane form, are produced by alternative splicing. The structure of ST2L protein shows a striking overall similarity to the type I IL-1 receptor. The 5'-end of human ST2 cDNAwas amplified using total RNA isolated from UT-7, a human leukemic cell line. Then we obtained a ST2 cDNA clone, which had unreported sequence at the 5'-end. Based on the newly cloned sequence, we amplified a *1 kb DNA fragment containing the promoter region of the ST2 gene by end trimming and cassette ligation- PCR.The previously reported promoter region of the ST2 gene was positioned downstream of the newly cloned one. The two promoter regions were separated by at least 8.0 kb. Four GATA-1 sequences were found in the newly cloned distal promoter region. Two of these GATA- 1 sequences were conserved between the human and mouse ST2 genes. UT-7 cells use multiple transcription initiation sites in both the proximal and distal promoters, while the transcription of the ST2 gene in TMl2 cells, a human fibroblastic cell line, start at a unique site. Although UT-7 cells use both distal and proximal promoters, the distal promoter is used dominantly for expression of both ST2 and ST2L mRNAs. On the other hand, almost all transcription in TMI2 cells start from the proximal promoter. In TMl2 cells, the human ST2 mRNA transcribed from the proximal promoter was remarkably increased up to 28 times at 6 h after serum stimulation. On the other hand, no transcripts initiated from the distal promoter were induced by serum stimulation. Human ST2L mRNA was also beneath the detectable leveL The production of the monoclonal antibodies against the human ST2 and ST2L proteins are under way.