Mek1 and Mek2 Functional Redundancy in Erythropoiesis

Investigating a Library of Flavonoids as Potential Inhibitors of a Cancer Therapeutic Target MEK2 Using in Silico Methods

The second leading cause of death in the world is cancer. Mitogen-activated protein kinase (MAPK) and extracellular signal-regulated protein kinase (ERK) 1 and 2 (MEK1/2) stand out among the different anticancer therapeutic targets. Many MEK1/2 inhibitors are approved and widely used as anticancer drugs. The class of natural compounds known as flavonoids is well-known for their therapeutic potential. In this study, we focus on discovering novel inhibitors of MEK2 from flavonoids using virtual screening, molecular docking analyses, pharmacokinetic prediction, and molecular dynamics (MD) simulations. A library of drug-like flavonoids containing 1289 chemical compounds prepared in-house was screened against the MEK2 allosteric site using molecular docking. The ten highest-scoring compounds based on docking binding affinity (highest score: -11.3 kcal/mol) were selected for further analysis. Lipinski's rule of five was used to test their drug-likeness, followed by ADMET predictions to study their pharmacokinetic properties. The stability of the best-docked flavonoid complex with MEK2 was examined for a 150 ns MD simulation. The proposed flavonoids are suggested as potential inhibitors of MEK2 and drug candidates for cancer therapy.

Fine-tuning of MEK signaling is pivotal for limiting B and T cell activation

MEK1 and MEK2, the only known activators of ERK, are attractive therapeutic candidates for both cancer and autoimmune diseases. However, how MEK signaling finely regulates immune cell activation is only partially understood. To address this question, we specifically delete Mek1 in hematopoietic cells in the Mek2 null background. Characterization of an allelic series of Mek mutants reveals the presence of distinct degrees of spontaneous B cell activation, which are inversely proportional to the levels of MEK proteins and ERK activation. While Mek1 and Mek2 null mutants have a normal lifespan, 1Mek1 and 1Mek2 mutants retaining only one functional Mek1 or Mek2 allele in hematopoietic cell lineages die from glomerulonephritis and lymphoproliferative disorders, respectively. This establishes that the fine-tuning of the ERK/MAPK pathway is critical to regulate B and T cell activation and function and that each MEK isoform plays distinct roles during lymphocyte activation and disease development.