Human megakaryoblastic cells (platelet precursor cells) grown in culture were sectioned for immunohistochemistry. Incubating these cells with a monoclonal antibody (JA8) directed against the human erythrocyte Ca2+ pump showed specific staining of the plasma membranes. PCR analysis of RNA from these cells demonstrated specific sequences for type HPMCA1, HPMCA2 and HPMCA4 Ca2+ pump isoforms. Western blot analysis of megakaryoblastic cells, whole platelets, and platelet membranes using monoclonal antibodies JA8, 5F10, and 3C2, directed against plasma membrane Ca2+ pump showed staining of a major band of Mr 120,000. Taken together, these studies demonstrate the existence of plasma membrane Ca2+ pump epitopes in human platelets and megakaryoblastic cells.
- Ca pump
ASJC Scopus subject areas