NMR Fragment Screening Hit Induces Plasticity of BRD7/9 Bromodomains

The complex biology associated with inhibition of bromodomain and extra‐terminal (BET) domains by chemical probes has attracted increasing attention, and there is a need to identify non‐BET bromodomain (BD) inhibitors. Several potent inhibitors of the BRD9 BD have recently been discovered, with anticancer and anti‐inflammation activity. However, its paralogue, BRD7 BD, remains unexploited. Here, we identified new chemotypes targeting BRD7 BD by using NMR fragment‐based screening. BRD7/9 BDs exhibit similar patterns of chemical‐shift perturbation upon the titration of hit compound 1 . The crystal structure revealed that 1 repels the Y222 group of BRD9 BD in a similar way to that for butyryllysine, but not acetyllysine and known inhibitors. Hit 1 induced less rearrangement of residue F161 of BRD9 BD than acetyllysine, butyryllysine, and crotonyllysine. Our study provides structural insight into a new generation of butyryllysine mimics for probing the function of BRD7/9 BD.     

Neurological Disorders and Risk of Arrhythmia

Neurological disorders including depression, anxiety, post-traumatic stress disorder (PTSD), schizophrenia, autism and epilepsy are associated with an increased incidence of cardiovascular disorders and susceptibility to heart failure. The underlying molecular mechanisms that link neurological disorders and adverse cardiac function are poorly understood. Further, a lack of progress is likely due to a paucity of studies that investigate the relationship between neurological disorders and cardiac electrical activity in health and disease. Therefore, there is an important need to understand the spatiotemporal behavior of neurocardiac mechanisms. This can be advanced through the identification and validation of neurological and cardiac signaling pathways that may be adversely regulated. In this review we highlight how dysfunction of the hypothalamic–pituitary–adrenal (HPA) axis, autonomic nervous system (ANS) activity and inflammation, predispose to psychiatric disorders and cardiac dysfunction. Moreover, antipsychotic and antidepressant medications increase the risk for adverse cardiac events, mostly through the block of the human ether-a-go-go-related gene (hERG), which plays a critical role in cardiac repolarization. Therefore, understanding how neurological disorders lead to adverse cardiac ion channel remodeling is likely to have significant implications for the development of effective therapeutic interventions and helps improve the rational development of targeted therapeutics with significant clinical implications.