John 'Jay' Schneekloth Jr., Ph.D.
Chemical Biology Laboratory
Building 376, Room 225C
Frederick, MD 21702-1201
Small Molecule Probes of Protein Sumoylation
The Small Ubiquitin-like Modifier (SUMO) is a ubiquitin-like posttranslational modification. Protein sumoylation is tightly linked with gene expression, as many of the known substrates for sumoylation are transcription factors. Furthermore, the aberrant regulation of sumoylation is linked to a number of cancers. Our laboratory has developed a novel electrophoretic mobility shift assay we are using in a high throughput screen of natural product extracts to identify naturally occurring small molecule sumoylation inhibitors. As a complementary approach, we are using fragment-based inhibitor design approaches to develop synthetic inhibitors of sumoylation. In addition, we have developed several synthetic substrates of sumoylation with the aim of gaining insight into substrate recognition and to identify active site-directed inhibitors. A major goal of this project is to establish a structural basis for chemical inhibition of sumoylation, and to gain insight into the structure and function of sumoylation enzymes and their role in cancer biology.
Identification of RNA- and DNA-binding Small Molecules Using Small Molecule Microarrays
The identification of selective RNA- and DNA-binding small molecules has been a longstanding challenge for chemical biology. Our approach to this problem is to use small molecule microarrays as a screening technology. We have assembled a library of 20,000 compounds that are used to screen diverse nucleic acid targets such as RNA hairpins and DNA G-quadruplexes. Most recently, we reported the identification of a druglike compound that binds to the HIV transactivation response (TAR) hairpin. This compound is not cationic, selectively binds to TAR in the context of the entire HIV 5'UTR, and rescues lymphoblastic cells from HIV-mediated cytopathicity without any observable toxicity. Future goals for this project involve the identification of small molecules that selectively interact with a broad variety of therapeutically relevant RNA targets.
Sztuba-Solinska J, Shenoy SR, Gareiss P, Krumpe LR, Le Grice SF, O'Keefe BR, Schneekloth JS Jr. Identification of biologically active, HIV TAR RNA-binding small molecules using small molecule microarrays. J Am Chem Soc. 2014;136(23):8402-10.
Kim YS, Keyser SG, Schneekloth JS Jr. Synthesis of 2',3',4'-trihydroxyflavone (2-D08), an inhibitor of protein sumoylation. Bioorg Med Chem Lett. 2014;24(4):1094-7.
Kim YS, Nagy K, Keyser S, Schneekloth JS Jr. An electrophoretic mobility shift assay identifies a mechanistically unique inhibitor of protein sumoylation. Chem Biol. 2013;20(4):604-13.
Kim J, Schneekloth JS Jr, Sorensen EJ. A chemical synthesis of 11-methoxy mitragynine pseudoindoxyl featuring the interrupted Ugi reaction. Chem Sci. 2012;3(9):2849-2852.
Noblin DJ, Page CM, Tae HS, Gareiss PC, Schneekloth JS, Crews CM. A HaloTag-based small molecule microarray screening methodology with increased sensitivity and multiplex capabilities. ACS Chem Biol. 2012;7(12):2055-63.