Related Experiment Videos
Identification of a 32K plasma membrane protein that binds to the myristylated amino-terminal sequence of p60v-src
1Department of Biology, Lewis Thomas Laboratory, Princeton University, New Jersey 08544.
Abstract:
The transforming protein of Rous sarcoma virus, p60v-src, is a myristylated membrane-bound phosphoprotein. Interaction of p60v-src with the plasma membrane is essential for transforming activity, and is mediated by association with a membrane-bound Src receptor protein. Evidence for the existence of an Src receptor is based on the ability of a myristylated peptide containing the N-terminal Src sequence to inhibit binding of p60v-src to plasma membranes in vitro: binding of p60v-src to a plasma membrane receptor is therefore mediated by N-terminal Src sequences. Here we report that a myristyl-Src peptide, but not the corresponding non-myristylated peptide, can be specifically crosslinked to a plasma membrane protein of relative molecular mass 32,000 (Mr32K). The 32K protein represents an Src-binding protein in the plasma membrane that is likely to be a component of the myristyl-Src receptor, and which could be involved in cellular transformation.
Insights
Myristylated Rous sarcoma virus p60v-src protein binds to plasma membranes via a specific receptor. A myristyl-Src peptide crosslinked to a 32K protein suggests this protein is part of the Src receptor, potentially involved in cell transformation.
Area of Science:
- Molecular Biology
- Virology
- Cell Biology
Background:
- The Rous sarcoma virus transforming protein, p60v-src, is a myristylated, membrane-bound phosphoprotein.
- p60v-src interaction with the plasma membrane is crucial for its transforming activity.
- This interaction is mediated by a membrane-bound Src receptor protein.
Purpose of the Study:
- To identify the Src receptor protein involved in p60v-src membrane binding.
- To investigate the role of N-terminal Src sequences and myristylation in receptor interaction.
Main Methods:
- Utilizing a myristyl-Src peptide and its non-myristylated counterpart.
- Employing specific crosslinking techniques to identify protein interactions.
- Analyzing plasma membrane proteins using relative molecular mass (Mr) determination.
Main Results:
- A myristyl-Src peptide, but not the non-myristylated version, specifically crosslinked to a plasma membrane protein.
- This crosslinked protein has a relative molecular mass of 32,000 (Mr32K).
- The Mr32K protein is identified as an Src-binding protein within the plasma membrane.
Conclusions:
- The Mr32K protein is likely a component of the myristyl-Src receptor.
- This receptor and its interaction with p60v-src may play a role in cellular transformation.
- N-terminal Src sequences and myristylation are critical for binding to this membrane receptor.