|Human, Monkey, Mouse, Rat|
Application Methods: Flow Cytometry, Immunofluorescence (Immunocytochemistry), Immunoprecipitation, Western Blotting
Background: Calcineurin, also known as protein phosphatase 2B (PP2B), is a calmodulin-dependent, calcium-activated, serine/threonine protein phosphatase composed of a catalytic subunit (calcineurin A) and a tightly bound regulatory subunit (calcineurin B) (1). Calcineurin A is highly homologous to protein phosphatases 1 and 2A. Calcineurin B, like calmodulin, contains four EF-hand, calcium-binding motifs.Calcineurin signaling has been implicated in a broad spectrum of cellular processes including cell-cycle regulation, stress response and apoptosis and is required for proper cardiovascular and skeletal muscle development (2,3). Calcineurin-mediated dephosphorylation of the nuclear factor of activated T cells (NFAT) transcription factor is essential for NFAT activation and nuclear translocation and early gene expression in T lymphocytes (2,3). Calcineurin is the target of the immunosuppressive drugs Cyclosporin A and FK506, both of which block the activation of quiescent T cells after T cell receptor engagement (2,3). Cyclosporin A and FK506 bind to the immunophilins, cyclophilin and FKBP respectively and the immunophilin-drug complex binds to calcineurin and blocks substrate binding.
|Bovine, Human, Monkey, Mouse, Rat|
Application Methods: Flow Cytometry, Immunohistochemistry (Paraffin), Immunoprecipitation, Western Blotting
Background: Translation repressor protein 4E-BP1 (also known as PHAS-1) inhibits cap-dependent translation by binding to the translation initiation factor eIF4E. Hyperphosphorylation of 4E-BP1 disrupts this interaction and results in activation of cap-dependent translation (1). Both the PI3 kinase/Akt pathway and FRAP/mTOR kinase regulate 4E-BP1 activity (2,3). Multiple 4E-BP1 residues are phosphorylated in vivo (4). While phosphorylation by FRAP/mTOR at Thr37 and Thr46 does not prevent the binding of 4E-BP1 to eIF4E, it is thought to prime 4E-BP1 for subsequent phosphorylation at Ser65 and Thr70 (5).