Design, synthesis, and X-ray structural studies of a series of highly potent, selective, and drug-like G protein-coupled receptor kinase 5 inhibitors.

G protein-coupled receptor kinase 5 (GRK5) has emerged as a potential drug development target against heart failure and cancer. A close homolog, GRK6 represents a therapeutic target for multiple myeloma. We have rationally designed a series of highly selective, potent, noncovalent, and drug-like GRK5 inhibitors.

Rescue of Familial Lecithin:Cholesterol Acyltranferase Deficiency Mutations with an Allosteric Activator.

Lecithin:cholesterol acyltransferase (LCAT) deficiencies represent severe disorders characterized by aberrant cholesterol esterification in plasma, leading to life-threatening conditions. This study investigates the efficacy of Compound 2, a piperidinyl pyrazolopyridine allosteric activator that binds the membrane-binding domain of LCAT, in rescuing the activity of LCAT variants associated with disease. The variants K218N, N228K, and G230R, all located in the cap and lid domains of LCAT, demonstrated notable activity restoration in response to Compound 2.

Structural and dynamic changes in P-Rex1 upon activation by PIP and inhibition by IP.

PIP-dependent Rac exchanger 1 (P-Rex1) is abundantly expressed in neutrophils and plays central roles in chemotaxis and cancer metastasis by serving as a guanine-nucleotide exchange factor (GEF) for Rac. The enzyme is synergistically activated by PIP and heterotrimeric Gβγ subunits, but mechanistic details remain poorly understood. While investigating the regulation of P-Rex1 by PIP, we discovered that Ins(1,3,4,5)P (IP) inhibits P-Rex1 activity and induces large decreases in backbone dynamics in diverse regions of the protein.

New Mechanisms Underlying Oncogenesis in Dbl Family Rho Guanine Nucleotide Exchange Factors.

Transmembrane signaling is a critical process by which changes in the extracellular environment are relayed to intracellular systems that induce changes in homeostasis. One family of intracellular systems are the guanine nucleotide exchange factors (GEFs), which catalyze the exchange of GTP for GDP bound to inactive guanine nucleotide binding proteins (G proteins). The resulting active G proteins then interact with downstream targets that control cell proliferation, growth, shape, migration, adhesion, and transcription.