ABSTRACT
The NEDD8-activating enzyme (NAE) initiates a protein homeostatic pathway essential for cancer cell growth and survival. MLN4924 is a selective inhibitor of NAE currently in clinical trials for the treatment of cancer. Here, we show that MLN4924 is a mechanism-based inhibitor of NAE and creates a covalent NEDD8-MLN4924 adduct catalyzed by the enzyme. The NEDD8-MLN4924 adduct resembles NEDD8 adenylate, the first intermediate in the NAE reaction cycle, but cannot be further utilized in subsequent intraenzyme reactions. The stability of the NEDD8-MLN4924 adduct within the NAE active site blocks enzyme activity, thereby accounting for the potent inhibition of the NEDD8 pathway by MLN4924. Importantly, we have determined that compounds resembling MLN4924 demonstrate the ability to form analogous adducts with other ubiquitin-like proteins (UBLs) catalyzed by their cognate-activating enzymes. These findings reveal insights into the mechanism of E1s and suggest a general strategy for selective inhibition of UBL conjugation pathways.
Subject(s)
Adenosine Monophosphate/metabolism , Cyclopentanes/metabolism , Enzyme Inhibitors/metabolism , Pyrimidines/metabolism , Ubiquitins/metabolism , Adenosine Monophosphate/chemistry , Binding Sites , Binding, Competitive , Cell Line, Tumor , Crystallography, X-Ray , Cyclopentanes/chemistry , Cyclopentanes/pharmacology , Enzyme Activation/drug effects , Enzyme Inhibitors/chemistry , Enzyme Inhibitors/pharmacology , Humans , NEDD8 Protein , Protein Structure, Tertiary , Pyrimidines/chemistry , Pyrimidines/pharmacology , Ubiquitins/chemistryABSTRACT
The clinical development of an inhibitor of cellular proteasome function suggests that compounds targeting other components of the ubiquitin-proteasome system might prove useful for the treatment of human malignancies. NEDD8-activating enzyme (NAE) is an essential component of the NEDD8 conjugation pathway that controls the activity of the cullin-RING subtype of ubiquitin ligases, thereby regulating the turnover of a subset of proteins upstream of the proteasome. Substrates of cullin-RING ligases have important roles in cellular processes associated with cancer cell growth and survival pathways. Here we describe MLN4924, a potent and selective inhibitor of NAE. MLN4924 disrupts cullin-RING ligase-mediated protein turnover leading to apoptotic death in human tumour cells by a new mechanism of action, the deregulation of S-phase DNA synthesis. MLN4924 suppressed the growth of human tumour xenografts in mice at compound exposures that were well tolerated. Our data suggest that NAE inhibitors may hold promise for the treatment of cancer.
Subject(s)
Antineoplastic Agents/pharmacology , Cyclopentanes/pharmacology , Enzyme Inhibitors/pharmacology , Neoplasms/drug therapy , Pyrimidines/pharmacology , Ubiquitin-Activating Enzymes/metabolism , Animals , Cell Line, Tumor , Cells, Cultured , Cullin Proteins/metabolism , Female , Humans , Mice , NEDD8 Protein , Proteasome Inhibitors , Transplantation, Heterologous , Ubiquitins/metabolismABSTRACT
Several potent, functionally active MCHr1 antagonists derived from quinolin-2(1H)-ones and quinazoline-2(1H)-ones have been synthesized and evaluated. Pyridylmethyl substitution at the quinolone 1-position results in derivatives with low-nM binding potency and good selectivity with respect to hERG binding.
Subject(s)
Quinazolines/chemistry , Quinazolines/pharmacology , Quinolones/chemistry , Quinolones/pharmacology , Receptors, Pituitary Hormone/antagonists & inhibitors , Animals , Mice , Quinazolines/pharmacokinetics , Quinolones/pharmacokineticsABSTRACT
Several potent and efficacious MCHr1 antagonists containing an ortho-amino benzamide or nicotinamide chemotype have been identified, exemplified by 28 and 50.
Subject(s)
Niacinamide/analogs & derivatives , Receptors, Somatostatin/antagonists & inhibitors , ortho-Aminobenzoates/chemical synthesis , Animals , Benzamides/chemical synthesis , Benzamides/pharmacokinetics , Benzamides/pharmacology , Inhibitory Concentration 50 , Mice , Mice, Inbred Strains , Niacinamide/pharmacokinetics , Niacinamide/pharmacology , Pharmacokinetics , Receptors, Somatostatin/agonists , Structure-Activity Relationship , Tissue Distribution , ortho-Aminobenzoates/pharmacokinetics , ortho-Aminobenzoates/pharmacologyABSTRACT
An efficient and highly enantioselective (>/=92% ee) catalytic method for conjugate addition of alkylzinc reagents to cyclic nitroalkenes is reported. Reactions are promoted in the presence of 0.5-5 mol % (CuOTf)2.C6H6 and 1-10 mol % of chiral amino acid-based phosphine ligands at 0 degrees C in toluene. The Cu-catalyzed reactions can be effectively carried out with small-, medium-, and large-ring nitroalkenes. Depending on the reaction conditions used, either the nitro or the corresponding alpha-substituted ketone product can be readily accessed by the present protocol.
Subject(s)
Alkenes/chemistry , Copper/chemistry , Hydrocarbons, Cyclic/chemical synthesis , Ketones/chemical synthesis , Nitro Compounds/chemistry , Organometallic Compounds/chemistry , Catalysis , Cyclohexanes/chemistry , Cyclohexenes , Hydrocarbons, Cyclic/chemistryABSTRACT
Highest enantioselectivities so far with dialkylzinc reagents! Quaternary carbon centers are formed enantioselectively through a Cu-catalyzed allylic substitution reaction that is promoted by pyridinyl peptide-based ligands in the presence of dialkylzinc reagents. The modularity of this new class of chiral ligands is exploited for reactivity and selectivity optimization.