Regulation of Gene Expression

Drosophila embryos stained to show the distribution of nanos mRNA (top panel) and Nanos protein (bottom panel). While nanos mRNA is concentrated at the posterior (right-hand side) of the embryo, substantial levels can be found distributed throughout the embryo. In contrast, Nanos protein specifically accumulates at the posterior of the embryo through a mechanism that ensures that only localized nanos mRNA is translated. Image courtesy of Craig Smibert.

The proper functioning of a cell and its ultimate developmental fate is determined by specific patterns of gene expression. These patterns are in part directed by signaling molecules that modulate a variety of regulatory cascades.

Gene expression begins in the nucleus, when regions of DNA are transcribed into RNA molecules, which are then processed, packaged into RNA-protein complexes, exported to the cytoplasm, transported to their ultimate destination, translated into proteins and then degraded. In addition it appears that eukaryotic transcription is inherently noisy, and it remains unclear how the relevant information is extracted from the genome.

Our research is devoted to understanding the molecular intricacies that are involved in interpretation of intercellular and intracellular regulatory signals and dictating a cell-type specific pattern of gene expression. Our interests include elucidation of the mechanisms that modulate chromatin assembly and structure; understanding the role of DNA-binding transcription factors in controlling differential transcription of a gene; determining how RNA transcripts are processed and packaged into RNA-protein complexes; understanding various quality control mechanisms that differentiate transcripts from transcriptional noise; investigating how mRNAs are transported, localized, translated and degraded.

Specific research programs in the Biochemistry Department utilize a range of model systems, from specialized mammalian cells in culture to fly embryos and employ biochemical, cell biological, computational and genome-wide approaches.