Problem: Qa-2 protein, the Ped gene product, is linked to the cell surface by a glycosylphosphatidylinositol (GPI) anchor. Some GPI-linked proteins can be spontaneously incorporated into the membranes of cells via a technique called "protein painting."We investigated whether Qa-2 could be painted onto T cells and embryos and whether the painted protein would be functional.
Method of study: Incorporation of Qa-2 into the membranes of T cells and embryos was measured by FACScan and Immuno-PCR, respectively. Function of Qa-2 was measured by cell proliferation.
Results: Qa-2 was incorporated by T cells and embryos and was functional.
Conclusion: GPI-linked Qa-2 protein "painted" onto both T cells and preimplantation embryos is functional, as shown by increased proliferation of T cells after cross-linking with anti-Qa-2 antibody, and increased rate of cleavage division of the embryos.