Welcome to the Gross Lab!

David Gross, PhD. Professor

The Gross Lab is located in the Medical School
LSU Health Sciences Center
1501 Kings Hwy
Shreveport, LA 71130-3932

Contact:
Phone: 318.675.5027
Fax: 318.675.5180
Email:dgross@lsuhsc.edu

Major Research Interests:

We use molecular and genetic approaches to dissect mechanisms by which the transcription of protein-encoding genes is regulated. A central focus of ours is on the role of Mediator, a highly conserved modular protein that bridges gene-specific activators with RNA polymerase II (Pol II). Mediator has been likened to a computer microprocessor that integrates multiple signals and converts these into an output–namely, highly precise Pol II-mediated transcription. Contrary to current models, we have obtained evidence for multiple Mediator complexes in the model Eukaryote Saccharomyces cerevisiae (baker's yeast). What their distinct functions might be is unknown, but are currently being investigated.

Intertwined with our interest in Mediator is the robust and highly dynamic regulation of thermal stress-responsive genes. These genes encode Molecular Chaperones and other cytoprotective Heat Shock Proteins (HSPs), and their expression in eukaryotes is regulated by a DNA-binding transcription factor, Heat Shock Factor (HSF1). HSF1 acts in concert with Mediator to dynamically regulate HSP genes, yet how it does so remains unclear, but is currently under investigation.

Recently, our laboratory made the striking observation that HSP genes undergo profound conformational changes, as they loop, 'crumple' (fold upon themselves accordion-style) and coalesce into transcriptionally active foci in response to heat shock. Notably, these foci are comprised of Hsf1-activated genes that engage in extensive physical contact; genes activated by Msn2/4, an alternative heat-inducible factor, do NOT coalesce, either with themselves or with HSP genes. Remarkably, conformational changes in HSP genes peak within the first 2.5 min of heat shock, then dissipate almost as quickly. Current efforts are directed towards understanding the molecular basis and biological significance of this fascinating and unprecedented phenomenon.

Google Scholar Citations