Related Experiment Videos
Nonmembrane associated dolichol in rat liver.
1Department of Biochemistry, University of Stockholm, Sweden.
Lipids
|January 1, 1992
Summary
Dolichol, a lipid essential for protein glycosylation, is found in rat liver cytoplasm and lysosomes. Its transfer between cellular compartments is independent of newly synthesized proteins.
Area of Science:
- Biochemistry
- Cell Biology
- Lipid Metabolism
Background:
- Dolichol is a key lipid involved in protein glycosylation.
- Understanding dolichol distribution is crucial for cellular function.
Purpose of the Study:
- To investigate the subcellular distribution of dolichol in rat liver.
- To elucidate the mechanism of dolichol transport within hepatocytes.
Main Methods:
- High-speed centrifugation to isolate cellular fractions.
- Gel filtration and density gradient centrifugation to characterize lipid particles.
- Incubation of isolated hepatocytes with liposomes.
- Puromycin treatment to inhibit protein synthesis.
Main Results:
- 9% of total liver dolichol was found in the supernatant after centrifugation.
- Dolichol was localized in 20 nm lipidic particles containing ubiquinone, cholesterol, phospholipids, and protein.
- Protein-free lipid particles (20-40 nm) containing dolichol were isolated from lysosomal lumen.
- Dolichol transfer from endoplasmic reticulum to lysosomes was unaffected by inhibited protein synthesis.
Conclusions:
- A significant amount of dolichol resides in the cytoplasm and lysosomal lumen.
- Dolichol translocation may not involve newly synthesized apoproteins.
- Dolichol likely plays a role in cellular translocation processes.