Gene Expression Regulation
Office: Shelby Center Room 369L
My lab is interested in understanding how cellular products modulate the function of ribosomes, the molecular machines that carry out protein production, to influence gene expression, cellular metabolism and phenotypic plasticity in bacterial cells. Cellular protein production can be controlled by diverse mechanisms since a substantial number of factors and events are involved during this process. Despite the diversity, the regulation of protein production keeps two common and essential characteristics: 1) the nature of the synthesized protein plays an important role in the modulation of the function of the ribosome; and 2) inhibition, or delay, in the ribosome function leads to the accumulation of intermediary products of the protein production, named peptidyl-tRNAs. The objective of our research is to identify genes which expression depends in the regulation of the ribosome function by detecting peptidyl-tRNAs expressed under relevant cell growth conditions. Also, determine the molecular mechanism(s) responsible for regulation of the ribosome function by cellular products. We expect to produce a gene-expression profiling technology to analyze in vivo the accumulation of peptidyl-tRNAs.
Martinez, A.K., Gordon, E., Sengupta, A., Shirole, N., Klepacki, D., Martinez-Garriga, B., Brown, L.M., Benedik, M.J., Yanofsky, C., Mankin, A.S., Vazquez-Laslop, N., Sachs, M.S., and Cruz-Vera, L.R. (2013). Interactions of the TnaC nascent peptide with rRNA in the exit tunnel enable the ribosome to respond to free tryptophan. Nucleic Acid Res. doi: 10.1093/nar/gkt923
Martinez, A. K., Shirole, N. H., Murakami, S., Benedik, M. J., Sachs, M. S. and Cruz-Vera, L. R. (2012). Crucial elements that maintain the interactions between the regulatory TnaC peptide and the ribosome exit tunnel responsible for Trp inhibition of ribosome function. Nucleic Acid Res. 40: 2247-2257.
Cruz-Vera, L. R., Squires, C. L., Sachs, M. S. and Yanofsky, C. (2011). Nascent polypeptide sequences that influence ribosome function. Curr. Opin. Microbiol. 14:160-166
Cruz-Vera, L. R., Yang, R. and Yanofsky, C. (2009). Tryptophan inhibits Proteus vulgaris TnaC leader peptide elongation, activating tna operon expression. J. Bacteriol. 191:7001-7006
Cruz-Vera, L. R., Rajagopal, S., Squires, C. L. and Yanofsky, C. (2005). Features of ribosome-peptidyl-tRNA interactions essential for tryptophan induction of tna operon expression. Mol. Cell. 19:333-343
Cruz-Vera, L. R., Magos-Castro, M. A., Zamora-Romo, E. and Guarneros, G. (2004). Ribosome stalling and peptidyl-tRNA drop-off during translation delay at AGA codons. Nucleic Acids Res. 18:4462-4468