1998 Fiscal Year Final Research Report Summary
ANALYSES OF EXOCYTOSIS SPECIFIC TO GROWTH FACTORS THAT HAVE NO SECRETION SIGNALS
| Project/Area Number |
09650879
|
|---|
| Research Category |
Grant-in-Aid for Scientific Research (C)
|
| Allocation Type | Single-year Grants |
|---|
| Section | 一般 |
|---|
| Research Field |
生物・生体工学
|
|---|
| Research Institution | OKAYAMA UNIVERSITY |
|---|
Principal Investigator |
SENO Masaharu FACULTY OF ENGINEERING,OKAYAMA UNIVERSITY ASSOCIATE PROFESSOR, 工学部, 助教授 (90243493)
|
|---|
| Co-Investigator(Kenkyū-buntansha) |
TADA Hiroko FACULTY OF ENGINEERING,OKAYAMA UNIVERSITY INSTRUCTOR, 工学部, 助手 (60271061)
YAMADA Hidenori FACULTY OF ENGINEERING,OKAYAMA UNIVERSITY PROFESSOR, 工学部, 教授 (80037613)
|
|---|
| Project Period (FY) |
1997 – 1998
|
| Keywords | SECRETION SIGNAL / GROWTH FACTOR / EXOCYTOSIS / SOLUBLE RECEPTOR / FIBROBLAST GROWTH FACTOR / CRIPTO |
|---|
| Research Abstract |
The mechanism of the transport from inside to outside of the cells are analyzed on basic fibroblast growth factor (bFGF) and Cripto (CR-I) because these two growth factors have been suggested not to have representative secretion signals and exocytosis of these molecules have not been elucidated.
First of all, bFGF was co-expressed with its soluble receptor in mouse fibroblast cell line BALB/c 3T3 by transfecting these two genes. And we found these transformants secreting bFGF molecule into the culture medium only when the soluble receptor co-expressed. Furthermore the transformant expressing both bFGF and soluble receptor showed high tumorigenicity in nude mice. These results strongly suggest that the exocytosis of bFGF is dependent on the presence of soluble receptors.
CR-l, which is a novel member of epidermal growth factor (EGF) family, has been characterized in various ways. Recombinant expression of CR-l in mammalian cells showed heterogeneous molecular weight of 20, 22, 24, and 28 Kd in Western blotting analyses. On the other hand, a specy of 18 Kd appeared in majority in the presence of tunicamycin which blocked the N-glycosilation of the site in the EGF motif of CR-l. This result is consistent with the cleaved size of CR-l peptide at the site theoretically predicted for secretion signal. However, the CR-l aminoterminally truncated by 36 mino acid residues was found to be secreted from the cells when the mutant gene was transfected to mammalian cell lines such as COS7 or CHO.This suggests that CR-l undergoes the pathway of exocytosis independent of the secretion signals. Together with the recent findings that CR-l related peptides are essentially involved in the development of embryos, characterization of CR- l is getting more important than ever.
|
