John 'Jay' Schneekloth Jr., Ph.D.
My laboratory uses chemical biology approaches to identify and study small molecule probes of gene expression. We are interested in two areas: protein sumoylation (a ubiquitin-like posttranslational modification that regulates transcription factor activity) and RNA-binding small molecules. We use synthetic chemistry and high throughput screening techniques to identify natural products or synthetic compounds that inhibit targets of interest.
1) organic chemistry, 2) natural products, 3) chemical biology, 4) ubiquitin-like signaling, 5) RNA-binding small molecules
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.
Selected Key Publications
Identification of biologically active, HIV TAR RNA-binding small molecules using small molecule microarrays.J. Am. Chem. Soc. 136: 8402-10, 2014. [ Journal Article ]
- Bioorg. Med. Chem. Lett. 24: 1094-7, 2014. [ Journal Article ]
An electrophoretic mobility shift assay identifies a mechanistically unique inhibitor of protein sumoylation.Chem. Biol. 20: 604-13, 2013. [ Journal Article ]
A chemical synthesis of 11-methoxy mitragynine pseudoindoxyl featuring the interrupted Ugi reaction.Chem Sci. 3: 2849-2852, 2012. [ Journal Article ]
A HaloTag-based small molecule microarray screening methodology with increased sensitivity and multiplex capabilities.ACS Chem. Biol. 7: 2055-63, 2012. [ Journal Article ]
Dr. Schneekloth received his undergraduate degree from Dartmouth College in 2001, where he worked with Prof. Gordon Gribble. He then moved to Yale University and obtained a Ph.D. from the chemistry department with Prof. Craig Crews in 2006. As a graduate student he studied natural product total synthesis and chemical biology relating to the ubiquitin-proteasome pathway. He then pursued an NIH postdoctoral fellowship with Prof. Erik Sorensen at Princeton University, where he worked on the development of a new multicomponent reaction and the application of this reaction to the synthesis of analgesic natural products. He returned to Yale in 2009 where he worked as a medicinal chemist at the Yale Small Molecule Discovery Center. In 2011, Dr. Schneekloth joined NCI where his research involves using synthetic chemistry and high throughput chemical biology approaches to develop chemical probes of signal transduction pathways and gene expression. Specific areas of interest include protein sumoylation (including mechanistic probes, natural products, and synthetic inhibitors) and the use of small molecule microarrays to identify RNA- and DNA-binding small molecules. He was awarded tenure in 2019.
|Sumirtha Balaratnam Ph.D.||Postdoctoral Fellow (Visiting)|
|Desta Doro Bume Ph.D.||Postdoctoral Fellow (Visiting)|
|David Calabrese Ph.D.||Postdoctoral Fellow (CRTA)|
|Shaifaly Parmar Ph.D.||Postdoctoral Fellow (Visiting)|
|Yihang Wang||Predoctoral Visiting Fellow (Graduate Student)|