Related Experiment Videos
Two developmentally regulated messenger RNAs differing in their coding region may exist for the myelin-associated
The Journal of Biological Chemistry
|December 10, 1984
Summary
Two distinct myelin-associated glycoprotein (MAG) proteins, p72MAG and p67MAG, were identified in mouse and rat brains. These MAG proteins exhibit different developmental expression patterns, suggesting distinct roles in myelination.
Area of Science:
- Neuroscience
- Molecular Biology
- Biochemistry
Background:
- Myelin-associated glycoprotein (MAG) is crucial for myelin sheath formation and function.
- Understanding the molecular diversity of MAG is essential for comprehending myelination processes.
Purpose of the Study:
- To identify and characterize different myelin-associated glycoprotein (MAG) related polypeptides in the brain.
- To investigate the developmental regulation of MAG gene expression.
Main Methods:
- In vitro translation of mouse and rat brain RNA using a rabbit reticulocyte lysate system.
- Immunoprecipitation to isolate MAG-related polypeptides.
- Peptide mapping and endoglycosidase H sensitivity assays to characterize the polypeptides.
- Analysis of mRNA expression during different developmental stages.
Main Results:
- Two distinct MAG polypeptides, p72MAG (72,000 Mr) and p67MAG (67,000 Mr), were identified and specifically immunoprecipitated.
- Both p72MAG and p67MAG are glycoproteins and share structural similarities.
- Translatable mRNAs for p72MAG and p67MAG show differential developmental expression, with p72MAG mRNA dominant early and p67MAG mRNA becoming dominant later in development.
Conclusions:
- The brain synthesizes at least two distinct MAG proteins with slightly different polypeptide structures.
- These MAG proteins are developmentally regulated, indicating distinct roles during myelination.
- The findings suggest the existence of two coordinately regulated mRNAs differing in their coding regions.