Cell-free transfer of sterols from dictyosome-like structures to plasma membrane vesicles of guinea pig testes |
| |
Authors: | Lisette Waits Stephanie Dunkle F E Wilkinson P Moreau Keri Safranski T Reust Dorothy M Morré D J Morré |
| |
Institution: | (1) Department of Foods and Nutrition, Purdue University, West Lafayette, Indiana;(2) Department of Medicinal Chemistry and Pharmacognosy, Purdue University, West Lafayette, Indiana |
| |
Abstract: | Summary Transfer of radiolabeled lipids from dictyosome-like structures (DLS) from testis tubules of the guinea pig as donor to unlabeled plasma membrane from testis tubules immobilized on nitrocellulose as acceptor was studied in a completely cell-free system. As a general label for lipids of the donor DLS, isolated testis tubules were incubated with 14C]acetate. Time- and temperature-dependent transfer of 14C]acetate labeled constituents was observed in the cellfree system. However, despite the fact that phospholipids and other constituents were highly labeled in the donor fraction, primarily radioactive sterols were transferred to the plasma membrane acceptor vesicles. Transfer at 37°C represented 0.4 to 0.7% of the total radiolabeled cholesterol at 37°C but little or no transfer occurred at 4°C. The sterols transferred exhibited Chromatographic mobilities corresponding to those of cholesterol and lanosterol. Similar results were obtained with 14C]mevalonic acid. In subsequent experiments, cholesterol transfer from DLS to plasma membrane was demonstrated by incubation of DLS with 3H]squalene which was converted into sterol or with 14C]cholesterol. Transfer of sterols required ATP, but not cytosol, and was both time- and temperature-dependent. DLS were more effective than either endoplasmic reticulum or plasma membrane as the donor fraction. The results from the cell-free analysis suggest a possible functional role of the DLS in sterol biogenesis and transfer to the plasma membrane during spermatid development.Abbreviations DLS
dictyosome-like structure(s)
- PBS
phosphatebuffered saline
- HEPES
4-(2-hydroxyethyl)-1-piperazineethanesulfonic acid
- BSA
bovine serum albumin |
| |
Keywords: | Cell-free sterol transfer Dictyosome-like structures Guinea pig Plasma membrane Sterols Testes |
本文献已被 SpringerLink 等数据库收录! |
|