2002 Fiscal Year Final Research Report Summary
Identification of GPI-anchored protein releasing factor using GPI-anchored GFP
| Project/Area Number |
13670118
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| Research Category |
Grant-in-Aid for Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
General medical chemistry
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| Research Institution | Osaka University |
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Principal Investigator |
KONDOH Gen Osaka University Graduate School of Medicine, Associate Professor, 医学系研究科, 助教授 (40243258)
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| Project Period (FY) |
2001 – 2002
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| Keywords | GPI anchor / GFP / Placental alkarin phosphatase / Mouse / Testis / Purification / Releasing factor / ACE |
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| Research Abstract |
To clarify the fate of glyeosylphosphstidylinositol (GPI) in mammals, we developed GPI-anchored green fluorescent protein (GFP-GPI) and transgenic mice carrying this fusion constract. When it was introduced to culture cells, the GFP-GPI protein was correctly sorted to plasma membranes and mierosomes depending on GPI biosynthesis. Transgenic mice carrying GFP-GPI were found to show a broad transgene expression. Historogically, a prominent polarized localization of GFP-GPI protein was observed in various epithelia, nervous system and liver, as well as non-polarized presence in non-epthelial tissues.
Surprisingly, the GFP-GPI protein showed high level secretion in exocrine glands and testis. What is the biological significance of this phenotype? How are GPI-anchored proteins released from membranes? To answer to these questions, we attempted to isolate which converts GPI-anchored proteins from the membrane attached form to the soluble form.
Processing and turnover of transmembrane polypeptides and extra-cellular matrix proteins are performed by particular metalloproteases, contributing to multiple biological processes at the cell surface. However the regulation of -anchored proteins, a class of proteins anchoring to the outer-leaflet of membrane lipid bilayer via glycophospholipid moiety, was not further clarified.
Here we found a metalloprotease, the angiotensin converting enzyme (ACE), release GPI-anchored proteins from the cell surface. ACE known to be a key regulator of blood pressure homeostasis cleaves various soluble small peptides, notably angiotensin I and bradykinin, thereby changing their biological activities and leading up-regulation of the blood pressure. The novel activity we found here suggests that ACE also contributes to membrane protein turnover and acts on more broad biological processes.
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Research Products
(13 results)
