Adipsin/Acylation Stimulating Protein System in Human Adipocytes: Regulation of Triacylglycerol Synthesis
| Autor: | Magdalena Maslowska, Joanne Forden, Allan D. Sniderman, Katherine Cianflone, Daniel A. K. Roncari, Allain Baldo |
|---|---|
| Rok vydání: | 1994 |
| Předmět: |
Acylation
Molecular Sequence Data Biochemistry Complement factor B Acylation stimulating protein Adipocytes Humans RNA Messenger Incubation Cells Cultured Triglycerides Serine protease Messenger RNA Base Sequence Dose-Response Relationship Drug biology Chemistry Stem Cells Serine Endopeptidases Cell Differentiation Blood Proteins Complement C3 Fibroblasts In vitro Complement C3a biology.protein Complement Factor D Function (biology) Complement Factor B |
| Zdroj: | Biochemistry. 33:9489-9495 |
| ISSN: | 1520-4995 0006-2960 |
| DOI: | 10.1021/bi00198a014 |
| Popis: | Through their capacity to store fatty acids as triacylglycerol molecules, adipocytes serve a vital physiologic role. This study presents further evidence that this process can be modulated in human adipocytes by the adipsin/acylation stimulating protein (ASP) pathway and suggests a novel function for the product of this system--ASP. The data demonstrate the following: (1) ASP stimulates triacylglycerol synthesis within adipocytes, and this occurs to a greater extent in differentiating than undifferentiated cells (242% +/- 32% vs 168% +/- 11%, p < 0.01, respectively, at an ASP concentration of 88 ng/mL; (2) ASP does not affect the Km for triacylglycerol synthesis but does substantially increase Vmax; (3) when ASP is generated in vitro through incubation of its precursor proteins under appropriate conditions, triacylglycerol synthesis increases to the same extent as when plasma-purified ASP is added to the medium; (4) human adipocytes contain mRNA for the specific serine protease adipsin and the two precursor proteins C3 and factor B required to interact for the production of ASP; and (5) the extent to which cultured differentiating adipocytes produce ASP is proportional to the degree to which they have accumulated triacylglycerol mass during differentiation (r2 = 0.7523, p < 0.0005). These findings provide the first evidence for the existence of the adipsin/ASP pathway in human adipocytes, and this may markedly enhance our understanding of the processes which regulate triacylglycerol clearance from plasma. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|