In contemporary models, eukaryotic cells segregate the synthesis of different classes of proteins;secretory/integral membrane proteins are made on the endoplasmic reticulum (ER) and soluble proteins in the cytosol. Recent studies of mRNA partitioning between the cytosol and ER compartments have, however, identified a prominent role for the ER in the synthesis of both soluble and secretory/membane proteins alike. In addition to describing new functions for the ER in global protein synthesis, these findings identify a significant gap in our understanding of how eukaryotic cells partition mRNAs between the two compartments and in turn regulate the synthesis of these two broad classes of proteins. To address this gap, we are focusing our research efforts to 1) understand how eukaryotic cells partition mRNAs between the cytosol and the endoplasmic reticulum (ER) and 2) determine how eukaryotic cells regulate the protein synthesis activity of the cytosol and ER compartments during homeostasis and cell stress. This research is expected to provide significant insights into the regulatory mechanisms governing protein synthesis in health and disease. In addition, this research will serve as a significant contribution to our understanding of the mRNA localization and protein synthesis pathways that are essential to eukaryotic life.
Three specific aims are proposed: i) Define the in vivo role of the SRP pathway in mRNA partitioning to the ER;ii) Identify the mRNA localization signals that confer non-canonical mRNA partitioning to the ER and iii) Define the global role of the ER compartment in cytosolic protein syntehsis. To address these specific aims, we will use mammalian tissue culture cell models and will emphasize established biochemical techniques of cell fractionation, cell biological analysis of reporter mRNA localization in situ and molecular biological analysis of the structure/function elements of mRNAs that confer ER localization. Many prominent human diseases, including obesity, diabetes and stroke activate cell stress responses that profoundly alter the types and amounts of proteins cells synthesize and consequently, cell viability. By understanding how cells decide which and how much of each protein to make, in health and disease, we will understand the basic mechanisms used by cells to respond to pathological stress. By understanding these mechanisms, we hope to identify new targets for therapeutic intervention.

National Institute of Health (NIH)
National Institute of General Medical Sciences (NIGMS)
Research Project (R01)
Project #
Application #
Study Section
Molecular Genetics B Study Section (MGB)
Program Officer
Ainsztein, Alexandra M
Project Start
Project End
Budget Start
Budget End
Support Year
Fiscal Year
Total Cost
Indirect Cost
Duke University
Anatomy/Cell Biology
Schools of Medicine
United States
Zip Code
Reid, David W; Nicchitta, Christopher V (2012) Primary role for endoplasmic reticulum-bound ribosomes in cellular translation identified by ribosome profiling. J Biol Chem 287:5518-27
Lacsina, Joshua R; Marks, Odessa A; Liu, Xiongfei et al. (2012) Premature translational termination products are rapidly degraded substrates for MHC class I presentation. PLoS One 7:e51968
Lacsina, Joshua R; LaMonte, Gregory; Nicchitta, Christopher V et al. (2011) Polysome profiling of the malaria parasite Plasmodium falciparum. Mol Biochem Parasitol 179:42-6
Yewdell, Jonathan W; Lacsina, Joshua R; Rechsteiner, Martin C et al. (2011) Out with the old, in with the new? Comparing methods for measuring protein degradation. Cell Biol Int 35:457-62
Chen, Qiang; Jagannathan, Sujatha; Reid, David W et al. (2011) Hierarchical regulation of mRNA partitioning between the cytoplasm and the endoplasmic reticulum of mammalian cells. Mol Biol Cell 22:2646-58
Jagannathan, Sujatha; Nwosu, Christine; Nicchitta, Christopher V (2011) Analyzing mRNA localization to the endoplasmic reticulum via cell fractionation. Methods Mol Biol 714:301-21
Jockheck-Clark, Angela R; Bowers, Edith V; Totonchy, Mariam B et al. (2010) Re-examination of CD91 function in GRP94 (glycoprotein 96) surface binding, uptake, and peptide cross-presentation. J Immunol 185:6819-30
Stephens, Samuel B; Dodd, Rebecca D; Lerner, Rachel S et al. (2008) Analysis of mRNA partitioning between the cytosol and endoplasmic reticulum compartments of mammalian cells. Methods Mol Biol 419:197-214
Stephens, Samuel B; Nicchitta, Christopher V (2008) Divergent regulation of protein synthesis in the cytosol and endoplasmic reticulum compartments of mammalian cells. Mol Biol Cell 19:623-32
Pyhtila, Brook; Zheng, Tianli; Lager, Patrick J et al. (2008) Signal sequence- and translation-independent mRNA localization to the endoplasmic reticulum. RNA 14:445-53

Showing the most recent 10 out of 11 publications