Covalent Modification of p53 by ()-1-(4-Methylpiperazin-1-yl)-3-(5-nitrofuran-2-yl)prop-2-en-1-one.

is commonly mutated in cancer, giving rise to loss of wild-type tumor suppressor function and increases in gain-of-function oncogenic roles. Thus, inhibition of mutant p53 and reactivation of wild-type function represents a potential means to target diverse tumor types. ()-1-(4-Methylpiperazin-1-yl)-3-(5-nitrofuran-2-yl)prop-2-en-1-one (NSC59984), first identified from a high-throughput screen, induces wild-type p53 signaling and antiproliferative effects while inhibiting mutant p53 gain-of-function activities.

Mutational analysis reveals the importance of residues of the access tunnel inhibitor site to human P-glycoprotein (ABCB1)-mediated transport.

Human P-glycoprotein (P-gp) utilizes energy from ATP hydrolysis for the efflux of chemically dissimilar amphipathic small molecules and plays an important role in the development of resistance to chemotherapeutic agents in most cancers. Efforts to overcome drug resistance have focused on inhibiting P-gp-mediated drug efflux. Understanding the features distinguishing P-gp inhibitors from substrates is critical.

Crystal structure and mechanistic studies of the PPM1D serine/threonine phosphatase catalytic domain.

Protein phosphatase 1D (PPM1D, Wip1) is induced by the tumor suppressor p53 during DNA damage response signaling and acts as an oncoprotein in several human cancers. Although PPM1D is a potential therapeutic target, insights into its atomic structure were challenging due to flexible regions unique to this family member. Here, we report the first crystal structure of the PPM1D catalytic domain to 1.

Second-site suppressor mutations reveal connection between the drug-binding pocket and nucleotide-binding domain 1 of human P-glycoprotein (ABCB1).

Human P-glycoprotein (P-gp) or ABCB1 is overexpressed in many cancers and has been implicated in altering the bioavailability of chemotherapeutic drugs due to their efflux, resulting in the development of chemoresistance. To elucidate the mechanistic aspects and structure-function relationships of P-gp, we previously utilized a tyrosine (Y)-enriched P-gp mutant (15Y) and demonstrated that at least 15 conserved residues in the drug-binding pocket of P-gp are responsible for optimal substrate interaction and transport. To further understand the role of these 15 residues, two new mutants were generated, namely 6Y with the substitution of six residues (F72, F303, I306, F314, F336 and L339) with Y in transmembrane domain (TMD) 1 and 9Y with nine substitutions (F732, F759, F770, F938, F942, M949, L975, F983 and F994) in TMD2.