2006 Fiscal Year Final Research Report Summary
Function of protein O-glycosylation in Aspergillus nidulans
| Project/Area Number |
17580067
|
|---|
| Research Category |
Grant-in-Aid for Scientific Research (C)
|
| Allocation Type | Single-year Grants |
|---|
| Section | 一般 |
|---|
| Research Field |
Applied microbiology
|
|---|
| Research Institution | KYUSHU UNIVERCITY |
|---|
Principal Investigator |
GOTO Masatoshi Kyushu University, Faculty of Agriculture, Research associate, 大学院農学研究院, 助手 (90274521)
|
|---|
| Co-Investigator(Kenkyū-buntansha) |
FURUKAWA Kensuke Kyushu University, Faculty of Agriculture, Professor, 大学院農学研究院, 教授 (90221556)
|
|---|
| Project Period (FY) |
2005 – 2006
|
| Keywords | Aspergillus / Oglycosylation / mannosyltransferase / cell wall integrity |
|---|
| Research Abstract |
In the present study, we attempted to clarify the function and role of protein O-glycosylation on the cell growth of filamentous fungus, Aspergillus nidulans as follows.
1. Functional analysis of cell wall sensor proteins (Wsc) as substrates for protein O-mannosyltransferase A (PmtA). The genes coded for WscA and WscB that shares ca. 30% sequence homology to yeast WSCl were cloned. Both WscA and WscB proteins are localized in the plasma membrane and O-glycosylated in A. nidulans as found in yeast Wscl. The disruptants of wscA and wscB genes were constructed. The wscB-disruptant does not show any defect in hyphal growth and conidia formation under experimental condition used. However, the wscA-disruptant shows hypersensitivity to low osmolarity, heat, and an inhibitor for cell wall synthesis, Congo red. The phenotype of the wscA-disruptant is in part similar to that of pmtA-disruptant. The result indicates that the growth defects observed in the pmtA-disruptant may be due to the under-or non-glycosylation of WscA protein, thereby the reduction or loss of function of this protein.
2. Functional analysis of pmtB and pmtC genes in A. nidulans. A.nidulans possesses additional two pmt genes termed pmtB and pmtC. We constructed the pmtB-and pmtC-disruptants. The pmtB-disruptant does not show a defect of growth rate and conidiation, however, this disruptant forms hyperbranching hyphae as compared to wt strain. The pmtC-disruptant shows a severe growth defect and abolishes the conidia formation. The hyphae are swollen all around the cells in this mutant. The phenotypes of the three pmt-disruptants are different, indicating that respective Pmt has substrate specificities in an independent manner. In the pmt-disruptants, secretory proteins are not glycosylated and cannot exert their original function. Thus, protein O-glycosylation affects the normal cell growth and differentiation of A.nidulans.
|
