Related Experiment Videos
Selective isoactin release from cultured embryonic skeletal muscle cells
The Journal of Cell Biology
|January 1, 1982
Summary
Researchers identified extracellular actin released from embryonic quail myoblasts. Nonmuscle isoactins were preferentially released, suggesting compartmentalization within developing muscle cells.
Area of Science:
- Cell Biology
- Molecular Biology
- Biochemistry
Background:
- Actin, a key cytoskeletal protein, exists in various isoforms.
- Understanding the secretion and localization of actin isoforms is crucial for cell development.
Purpose of the Study:
- To identify and characterize the major polypeptide released into the culture medium of embryonic quail myoblasts.
- To investigate the origin and nature of the released polypeptide.
Main Methods:
- Two-dimensional gel electrophoresis and autoradiography of [35S]L-methionine labeled myoblasts.
- DNAse-I Sepharose adsorption and tryptic peptide mapping for polypeptide identification.
- Bio-Gel A-5m chromatography to assess filament formation.
Main Results:
- A 43,000 molecular weight polypeptide with an isoelectric point of 5.4 was identified as actin.
- Tryptic peptide mapping confirmed the identity of the released polypeptide as intracellular actin.
- Released actin was non-filamentous and preferentially composed of nonmuscle isoactins.
- Actin release was observed in clonal myoblast and purified myotube cultures, excluding fibroblast contamination.
Conclusions:
- Embryonic quail myoblasts preferentially release nonmuscle isoactins into the extracellular environment.
- This selective release suggests compartmentalization of actin isoforms within developing muscle cells, with nonmuscle isoactins located near the cell surface.