Related Experiment Videos
A lamin B receptor in the nuclear envelope.
1Laboratory of Cell Biology, Howard Hughes Medical Institute, Rockefeller University, New York, NY 10021.
Summary
Researchers identified a specific protein, p58, that acts as a receptor for lamin B. This discovery sheds light on how the nuclear lamina attaches to the nuclear membrane, crucial for cell structure and function.
Area of Science:
- Cell Biology
- Molecular Biology
- Biochemistry
Background:
- The nuclear lamina provides structural support to the nucleus.
- The interaction between the nuclear lamina and the nuclear envelope is essential for nuclear stability.
- Specific receptors mediating lamin-nuclear membrane interactions are not fully characterized.
Purpose of the Study:
- To identify and characterize the receptor for lamin B in avian erythrocyte nuclear membranes.
- To elucidate the role of this receptor in anchoring the nuclear lamina to the nuclear envelope.
Main Methods:
- Solution binding assays using radiolabeled lamins (lamin B and lamin A).
- Ligand blotting assays to identify interacting proteins.
- Antibody production and validation against the putative receptor.
- Cell fractionation and indirect immunofluorescence microscopy for protein localization.
Main Results:
- Purified lamin B binds saturably and specifically to lamin-depleted nuclear membranes (Kd ≈ 0.2 μM).
- Lamin B binding is significantly higher than lamin A binding and is competitively inhibited.
- A 58-kDa integral membrane protein (p58) was identified as a lamin B receptor.
- Antibodies against p58 recognized a single nuclear protein and partially blocked lamin B binding.
- p58 is localized to the nuclear periphery.
Conclusions:
- A 58-kDa integral membrane protein (p58) functions as a specific receptor for lamin B.
- p58 mediates the attachment of the nuclear lamina to the nuclear envelope.
- This interaction is critical for maintaining nuclear structure and organization.