The P55 protein affected by v-mos expression is vimentin

Area of Science:

• Molecular Biology
• Cell Biology
• Virology

Background:

• The viral mos gene (v-mos) from Moloney murine sarcoma virus encodes proteins that affect cellular processes.
• A specific 55,000-Mr cellular polypeptide is downregulated in cells expressing the v-mos gene.
• Intermediate filament proteins play crucial roles in cellular structure and function.

Purpose of the Study:

• To identify the 55,000-Mr cellular polypeptide recognized by an antiserum raised against a v-mos peptide.
• To investigate the relationship between the v-mos gene product and this normal cellular protein.

Main Methods:

• Generation of rabbit antiserum against a synthetic peptide derived from the v-mos sequence.
• Immunodetection of cellular proteins using the generated antiserum.
• Comparative analysis of the detected 55,000-Mr polypeptide with known cellular proteins, including vimentin, through gel electrophoresis, isoelectric focusing, immunofluorescence, and peptide mapping.

Main Results:

• The antiserum specifically recognized both v-mos gene products and a 55,000-Mr polypeptide in various adherent cell types.
• The 55,000-Mr polypeptide was identified as vimentin, a major intermediate filament protein.
• Vimentin levels were found to be reduced in cells expressing the v-mos gene.

Conclusions:

• The viral mos gene product likely interferes with the expression or stability of cellular vimentin.
• This finding suggests a potential role for vimentin in the cellular changes induced by the v-mos oncogene.
• The study provides a tool (antiserum) for further investigation into v-mos and vimentin interactions.