Epstein-Barr virus latent membrane protein 2A blocks calcium mobilization in B lymphocytes.
LMP2A is expressed in latent Epstein-Barr virus (EBV) infection and interacts with LMP1 and members of the src tyrosine kinase family in the plasma membrane. Since tyrosine kinase mediate receptor-induced changes in intracellular free calcium, the effect of LMP2A on receptor-mediated intracellular calcium mobilization was evaluated by stably expressing LMP2A in an EBV-negative Burkitt tumor cell line (BJAB) or in LMP1-converted BJAB cells. LMP2A significantly blocked calcium mobilization following class II, CD19, or immunoglobulin M cross-linking. LMP2A effects were partially reversed in LMP1-converted cell lines. These results are compatible with LMP2A acting in latent B-lymphocyte infection to downmodulate LMP1 effects on cell growth or to inhibit induction of lytic EBV infection in specific human tissues following receptor ligation.
Miller
C L
CL
Department of Medicine, Harvard Medical School, Boston, Massachusetts 02115.
Longnecker
R
R
Kieff
E
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D015703:Antigens, CD / Q000378:metabolism; D018941:Antigens, CD19; D000944:Antigens, Differentiation, B-Lymphocyte / Q000378:metabolism; D000956:Antigens, Viral / Q000235:genetics / Q000378:metabolism* / Q000494:pharmacology; D001402:B-Lymphocytes / Q000187:drug effects / Q000378:metabolism*; D002051:Burkitt Lymphoma; D002118:Calcium / Q000378:metabolism*; D015536:Down-Regulation; D005434:Flow Cytometry; D005802:Genes, MHC Class II; D006801:Humans; D007075:Immunoglobulin M / Q000378:metabolism; D008213:Lymphocyte Activation / Q000502:physiology*; D011956:Receptors, Cell Surface / Q000378:metabolism; D014162:Transfection; D014407:Tumor Cells, Cultured; D014763:Viral Matrix Proteins / Q000235:genetics / Q000378:metabolism* / Q000494:pharmacology
D015703:Antigens, CD; D018941:Antigens, CD19; D000944:Antigens, Differentiation, B-Lymphocyte; D000956:Antigens, Viral; C037662:EBV-associated membrane antigen, Epstein-Barr virus; D007075:Immunoglobulin M; D011956:Receptors, Cell Surface; D014763:Viral Matrix Proteins; D002118:Calcium