Related Experiment Videos
Occurrence of selenium-containing tRNAs in mouse leukemia cells
Summary
Selenium is incorporated into mouse leukemia cell transfer RNAs (tRNAs). The study found selenium exists as a modified nucleoside within these tRNAs, not a selenoamino acid.
Area of Science:
- Biochemistry
- Molecular Biology
- Cell Biology
Background:
- Selenium incorporation into transfer RNA (tRNA) polynucleotide structures is known in microorganisms.
- The presence and form of selenium in mammalian tRNAs remain less understood.
Purpose of the Study:
- To investigate the nature of selenium incorporation into tRNA from mouse leukemia cells.
- To characterize the chemical form and location of selenium within these tRNAs.
Main Methods:
- Isolation of 75Se-labeled selenium-containing species from mouse leukemia cell tRNA preparations.
- Analysis of size, ribonuclease sensitivity, and chromatographic properties.
- pH stability studies and High-Performance Liquid Chromatography (HPLC) of enzymic digests.
Main Results:
- A major 75Se-labeled selenium-containing species was isolated, similar in size and ribonuclease sensitivity to Escherichia coli tRNAs.
- The species exhibited hydrophobic characteristics.
- The selenium component was unstable at neutral-to-alkaline pH but stable at acidic pH, ruling out esterified selenoamino acids.
- HPLC analysis identified selenium-containing hydrophobic products, likely selenonucleosides.
Conclusions:
- The selenium in mouse leukemia cell tRNAs is likely present as a selenium-modified nucleoside.
- This finding contributes to understanding selenium's role in mammalian nucleic acid modifications.