Biochemical Characterization of Native Schwannomin/Merlin
Abstract
The NF2 tumor suppressor protein, termed Merlin/Schwannomin, is a member of the protein 4.1 superfamily that functions as a linker of the plasma membrane to the cytoskeleton. A major limitation in understanding the biochemical function of NF2 protein is the unavailability of purified native protein from human tissues. Our discovery of the presence of NF2 protein in human erythrocytes allowed us to develop a purification procedure that affords homogeneous NF2 protein in its native state. Selective extraction of ghosts in the low ionic strength buffer indicated that the bulk of NF2 protein remains associated with spectrin-actin depleted inside-out-vesicles. Quantitative removal of NF2 protein by potassium iodide shows that it is tightly associated with the membrane. Interestingly, the NF2 protein was completely solubilized in 0.5% Triton X-100 at high but not at low ionic strength. These results suggest a novel mode of NF2 protein association with the membrane that is distinct from protein 4.1. We devised a purification strategy to isolate NF2 protein from human erythrocytes. Identification of NF2 protein as a constituent of erythrocyte membrane provides a unique opportunity to study the biochemical properties of native protein, and identify proteins that interact with NF2 protein in the mammalian plasma membrane.
Document Details
- Document Type
- Technical Report
- Publication Date
- Sep 01, 2004
- Accession Number
- ADA428957
Entities
People
- Athar Chishti
Organizations
- University of Illinois at Chicago