We broadly investigate the mechanisms used in cells to regulate gene expression at the translational level. Some work began soon after the lab's launch in January of 2016 and expanded once full setup and cleaning of the lab space was accomplished, and unit members were hired. Research has focused on the question of how ribosomes are disassembled following the completion of translation at stop codons to allow the ribosomal subunits to be reused for new rounds of translation. This recycling of subunits is critical because its failure can lead to a shortage of ribosomes, limiting the cell's ability to make protein. This process begins when the stop codon is decoded by the canonical release factors, eRF1 and eRF3. Following GTP hydrolysis by eRF3, the ATPase Rli1 (ABCE1 in higher eukaryotes) separates the two subunits from each other. In prior work, we established that lack of sufficient Rli1 in the cell leads to an accumulation of ribosomes in the 3'UTR and the translation of short open reading frames. The recycling factor ABCE1 is known to be upregulated in many types of cancer, suggesting that ribosome recycling is critical in cancer cells, potentially as a way to ensure an adequate supply of recycled ribosomes for new rounds of translation during rapid proliferation. We believe this process to also be critical during the innate immune response because the activity of ABCE1 is thought to modulated by genes that are upregulated by interferon stimulation. A better understanding of the mechanism of ribosome recycling is therefore important for overcoming major challenges to human health. We have begun work on deciphering the rules and factors involved in ribosome reinitiation downstream of the stop codon by using masspec and ribosome footprint profiling approaches. We are also interested in the biological role for 3'UTR ribosomes. We are examining the effects of nutrient deprivation stress (yeast) and simulated viral infection (human cell lines), for example, in reducing the efficiency of termination and recycling. Early results have shown we can stimulate the cell's antiviral response and we now are developing computational methods for analyzing ribosome profiling of these cell lines. Finally, we have also begun designing constructs to take advantage of new single molecule fluorescence technologies for imaging translation on single mRNAs in cells, such as SunTag and fluorescently-labeled RNA stem loop binding proteins.
| Guydosh, Nicholas R; Kimmig, Philipp; Walter, Peter et al. (2017) Regulated Ire1-dependent mRNA decay requires no-go mRNA degradation to maintain endoplasmic reticulum homeostasis in S. pombe. Elife 6: |
| Guydosh, Nicholas R; Green, Rachel (2017) Translation of poly(A) tails leads to precise mRNA cleavage. RNA 23:749-761 |
| de Vasconcellos, Jaira F; Tumburu, Laxminath; Byrnes, Colleen et al. (2017) IGF2BP1 overexpression causes fetal-like hemoglobin expression patterns in cultured human adult erythroblasts. Proc Natl Acad Sci U S A 114:E5664-E5672 |
| Young, David J; Guydosh, Nicholas R (2016) Silence without stress. Elife 5: |
| Woolstenhulme, Christopher J; Guydosh, Nicholas R; Green, Rachel et al. (2015) High-precision analysis of translational pausing by ribosome profiling in bacteria lacking EFP. Cell Rep 11:13-21 |
| Guydosh, Nicholas R; Green, Rachel (2014) Dom34 rescues ribosomes in 3' untranslated regions. Cell 156:950-62 |
