A platelet alpha-granule membrane protein (GMP-140) is expressed on the plasma membrane after activation - PubMed (original) (raw)

A platelet alpha-granule membrane protein (GMP-140) is expressed on the plasma membrane after activation

P E Stenberg et al. J Cell Biol. 1985 Sep.

Abstract

We have previously characterized a monoclonal antibody, S12, that binds only to activated platelets (McEver, R.P., and M.N. Martin, 1984, J. Biol. Chem., 259:9799-9804). It identifies a platelet membrane protein of Mr 140,000, which we have designated as GMP-140. Using immunocytochemical techniques we have now localized this protein in unstimulated and thrombin-stimulated platelets. Polyclonal antibodies to purified GMP-140 were used to enhance the sensitivity of detection. Nonpermeabilized, unstimulated platelets, incubated with anti-GMP-140 antibodies, and then with IgG-gold probes, showed very little label for GMP-140 along their plasma membranes. In contrast, thrombin-stimulated platelets exhibited at least a 50-fold increase in the amount of label along the plasma membrane. On frozen thin sections of unstimulated platelets we observed immunogold label along the alpha-granule membranes. We also employed the more sensitive technique of permeabilizing with saponin unstimulated platelets in suspension, and then incubating the cells with polyclonal anti-GMP-140 antibodies and Fab-peroxidase conjugate. Alpha-granule membranes showed heavy reaction product, but no other intracellular organelles were specifically labeled. These results demonstrate that GMP-140 is an alpha-granule membrane protein that is expressed on the platelet plasma membrane during degranulation.

PubMed Disclaimer

Similar articles

Cited by

References

    1. Nature. 1970 Aug 15;227(5259):680-5 - PubMed
    1. J Cell Biol. 1985 Apr;100(4):1284-94 - PubMed
    1. Circ Res. 1978 Mar;42(3):402-9 - PubMed
    1. Annu Rev Med. 1978;29:41-9 - PubMed
    1. Proc Natl Acad Sci U S A. 1979 Sep;76(9):4350-4 - PubMed

Publication types

MeSH terms

Substances

LinkOut - more resources