BBS Faculty Member - Keith Joung

Keith Joung

Department of Pathology

Massachusetts General Hospital-East
Molecular Pathology Unit
149 13th St., 6th Floor
Charlestown, MA 02129
Tel: 617-726-9462
Fax: 617-726-5684
Lab Members: 3 postdoctoral fellows, 3 graduate students, 5 technicians
Visit my lab page here.

The Joung Laboratory seeks to develop and apply robust technologies for editing the genome and epigenome to understand human biology and treat disease. We have extensive experience with genome editing, epigenome editing, protein engineering, building and screening of large-scale combinatorial libraries, automation, and the study of protein-DNA interactions. Over the last several years, we have developed publicly available, open-source platforms for engineering zinc fingers, transcription activator-like effectors (TALEs), and clustered, regularly interspaced, short palindromic repeat (CRISPR)-Cas proteins and pioneered the use of these platforms to address important questions and limitations in biological research. We have also begun to explore the use of these platforms to modulate both gene sequence and gene expression for therapeutic applications.

Targeted genome editing using nucleases with customizable specificities
Our lab has developed highly robust methods for engineering zinc finger nucleases (ZFNs), TALE nucleases (TALENs), and CRISPR-Cas9 nucleases. Using these three platforms, we (and our collaborators) have introduced targeted DNA alterations with high efficiencies into specific genomic loci in zebrafish, plants, or human somatic and pluripotent stem cells. These alterations result from repair of nuclease-induced double-stranded DNA breaks by normal cellular repair processes (non-homologous end-joining or homologous recombination). Ongoing projects in the lab are aimed at defining and improving the specificities of these platforms and optimizing the editing capabilities of these methods for eventual therapeutic applications. We are also continuing to explore the development of novel technologies that will enable high-throughput genome editing.

Targeted epigenome editing to induce alterations in endogenous gene expression
We have demonstrated that engineered zinc fingers, TALEs, and CRISPR-Cas proteins can all be used to construct artificial transcription factors that can robustly alter the expression of endogenous human genes. More recently, we have also shown that engineered TALEs can be used to direct histone modifications that can inactivate endogenous gene enhancers (work done with Bradley Bernstein's lab) and to direct demethylation of specific promoter CpGs that can lead to increases in endogenous gene expression. These studies provide important proofs-of-principle that customized DNA targeting technologies can be used to modify the epigenome. In the longer-term, we seek to develop methods and technologies that will allow us to stably reprogram and re-wire the expression of endogenous genes in human cells. These capabilities will have important research applications for studying gene regulation but may also provide novel tools for altering the expression of disease-associated genes.

Last Update: 6/19/2014


For a complete listing of publications click here.



Our laboratory develops robust protein engineering methods for constructing artificial "designer" DNA-binding domains. Our efforts focus on Cys2His2 zinc fingers and Xanthomonas Transcription Activator-Like Effector (TALE) repeat domains, two motifs that can be used to create proteins with customized DNA-binding specificities. We are also exploring the applications of engineered zinc finger and TALE repeat domain proteins for biological research and gene therapy.

Engineering "designer" DNA-binding domains with novel specificities
The Joung lab develops robust and high-throughput methods for rapidly engineering synthetic zinc finger and TALE repeat domain proteins with novel, defined DNA-binding specificities. We are also developing approaches to define and further improve the activities and specificities of both zinc finger and TALE domain proteins.

Engineered nucleases for targeted, highly efficient genome editing
Zinc finger nucleases (ZFNs) and TALE nucleases (TALENs), consisting of designer zinc fingers or TALE domains fused to a non-specific endonuclease domain, can be used to introduce targeted DNA alterations with high efficiency at specific genomic loci in a variety of different cell types and organisms ranging from human to Drosophila. These alterations result from repair of nuclease-induced double-stranded DNA breaks by normal cellular repair processes (non-homologous end-joining or homologous recombination). On-going projects in the lab are aimed at developing the ZFN and TALEN genome modification methodologies and using them for applications in biological research and gene therapy.

Altering cellular phenotypes using combinatorial transcription factor libraries
We have recently constructed large combinatorial libraries of zinc finger domains which can be fused to various transcriptional regulatory domains (e.g.--activation or repression domains). We are introducing these libraries into human cells to induce specific desired phenotypes and cellular states. We are exploring similar strategies based on combinatorial libraries of TALE-based DNA-binding domains.

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