1996 Fiscal Year Final Research Report Summary
Elucidation of Functional Implication of Post-translational Tyrosine Sulfation
| Project/Area Number |
06660117
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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 |
応用微生物学・応用生物化学
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| Research Institution | Miyazaki University |
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Principal Investigator |
SUIKO Masahito Miyazaki University, Department of Biological Resources Sciences, Associate Professor, 農学部, 助教授 (00128357)
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| Project Period (FY) |
1994 – 1996
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| Keywords | Tyrosine Sulfation / Post-translational Modification / Sulfotransferase / Golgi Body / Sorting / Microsome / Complement C3 / Fibronectin |
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| Research Abstract |
By employing the affinity gel fraction technique, we have detected a 175 kDa tyrosine-O-sulfate (TyrS)-binding protein in sodium choleate extracts of the microsomal membrane fractions of bovine liver and pancreas, as well as canine liver and pancreas. Western blot analysis revealed the presence of the bovine liver TyrS-binding protein in complexes with tyrosine-sulfated proteins both in vivo and in vitro, suggesting the putative role of the former being the receptor for the latter. Using filter-grown Madin-Darby canine kidney (MDCK) cells as a model, it was demonstrated that the tyrosine-sulfated proteins synthesized were predominantly secreted into the apical medium. The results further indicate the production and differential polarized secretion of different sulfated forms of the two major secretory proteins produced by MDCK cells, fibronectin (FN) and an 80 kDa glycoprotein (gp 80), with their tyrosine-sulfated forms being predominantly secreted from the apical surface. Treatment of filtergrown MDCK cells with glycosylation inhibitors, swainsonine and 1-deoxymannojirimycin, appeared to enhance the apical secretion of tyrosine-sulfated FN and gp 80. A similar 175 kDa membrane-bound "TyrS trceptor." cross-reactive toward antiserum against the canine liver TyrS receptor. was shown to be present in MDCK cells. Pulse-chase experiments revealed its presence in complexes with newly synthesized FN and gp 80. A hypothetical model for TyrS residues serving as an apical targeting signal during the biosynthetic transport of tyrosine-sulfated proteins. as mediated by the TyrS receptor. in MDCK cells is proposed.
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