eEF2K (Ser-445), phospho-specific polyclonal, anti-human, mouse, rat, fish

Background:
Eukaryotic elongation factor 2 (eEF2) catalyzes the translocation of peptidyl-tRNA from the A site to the P site on the ribosome. eEF2 kinase (eEF2K) phosphorylates and inactivates eEF2, resulting in the inhibition of peptide-chain elongation. eEF2K is normally dependent on Ca2+ ions and calmodulin, and can be activated by PKA in response to elevated cAMP levels during cell stress- or starvation-related conditions. Regulation of eEF2K occurs through phosphorylation at multiple sites. Ser-78 phosphorylation is required for calmodulin binding and eEF2K activity, while phosphorylation of Ser-500 is required for Ca2+/calmodulin-independent kinase activity. Thr-348 and Ser-445 are two of the major autophosphorylation sites required for kinase activity. Inhibitory phosphorylation may also regulate eEF2K, since phosphorylation at Ser-359 by SAPK4/p38δ causes inactivation of eEF2K. In addition, Ser-398 phosphorylation is required for eEFK2 induced autophagy. Thus, multisite phospho-regulation of eEF2K may be important for proper control of eEF2K activity and protein translation.

Immunogen: Phospho-eEF2K (Ser-445) synthetic peptide (coupled to carrier protein) corresponds to amino acids surrounding Ser-445 in human eEF2K. This sequence is well conserved in rat, mouse, and fish eEF2K, and has low homology to other proteins.

Specificity: The antibody was cross-absorbed to unphosphorylated eEF2K (Ser-445) before affinity purification using phospho-eEF2K (Ser-445) peptide (without carrier). This antibody detects a 105 kDa* protein corresponding to the molecular mass of eEF2K on SDS-PAGE immunoblots of Jurkat cells treated with Calyculin A, and this reactivity is removed after lambda phosphatase treatment.

Buffer/Storage:
Rabbit polyclonal, affinity-purified antibody is supplied in 100µl phosphate-buffered saline, 50% glycerol, 1 mg/ml BSA, and 0.05% sodium azide. Store at –20°C. Stable for 1 year.