We study retroviruses, particularly the integration of retroviral cDNA.

Retroviruses have an RNA genome. After the virus enters a cell, the viral enzyme reverse transcriptase copies the RNA into a linear double-stranded cDNA. The viral cDNA is parLifeCyclet of a poorly understood complex of viral and host proteins termed the pre-integration complex (PIC). The PIC includes the viral enzyme integrase. The PIC moves to the nucleus where integrase catalyzes the covalent joining of the viral cDNA genome to the host DNA. The integrated viral genome is called the provirus. After integration the viral genome is transcribed and translated by host machinery to generate progeny viruses. Alternatively the provirus may become transcriptionally silent or latent. After integration the viral genome is stable and is able to produce new viruses as long as the cell lives.

Biochemistry of Integration

We purify recombinant integrase of prototype foamy virus (PFV), mouse mammary tumor virus (MMTV), and human immunodeficiency virus (HIV-1). We can assemble these integrases with DNA oligonucleotides mimicking the viral cDNA ends to functional intasome complexes. We use the intasomes to study integration in vitro.

Single Molecule Studies and Chromatin Target DNA

How does an integration complex search target DNA for site to perform integration? How does the search happen when DNA is bound by nucleosomes in the context of chromatin? What features of nucleosomes and/or integrase are important for the search? These are key questions we are trying to answer.

CRISPR genome editing of retroviral proviruses

CRISPR genome editing of the HTLV-1 provirus may prove useful in the treatment of ATL or HAM/TSP patients. The HTLV-1 proviral genome is genetically stable and the associated diseases have no effective treatments.