The objective of the proposed NMR studies is to determine the protein-protein interactions involved in the assembly of a bacterial nanoinjector that is essential in the pathogenesis of many bacterial pathogens. The nanoinjector is a needle-like macromolecular assembly and forms the structural part of bacterial protein export machinery, the type III secretion system (T3SS). The T3SS also consists of effector proteins, which are injected into the host cell cytoplasm, and chaperones, which form complexes with T3SS proteins while inside the bacterial cytoplasm. The T3SS needle apparatus is assembled from over 20 different proteins and consists of a basal structure anchored on the bacterial membranes, the needle itself on the bacterial surface, a tip complex, and a translocon. The translocon is the membrane spanning structure that punctures a hole on the host cell membrane to allow the passage of bacterial proteins into the host cell cytoplasm. On the first round of funding, we have determined how the needle protein interacts with the tip protein. Currently, how the tip protein interacts with the translocon is completely unknown. For this renewal, our Aim #1 is to determine how the tip protein interacts with the translocon proteins. Another unknown is how the tip proteins interact with their chaperones, thus our Aim #2 is to determine how the tip proteins interact with their chaperones. To advance our understanding of the biology of the T3SS, our NMR studies will be complemented with electron microscopy and functional assays. Many pathogens rely on the type III secretion system to infect millions of people worldwide. Because the needle apparatus is exposed on the bacterial surface, disrupting the needle assembly is an attractive target for the development of novel anti- infectives. This approach requires a detailed understanding of the protein-protein interactions involved in needle assembly.
Before the age of antibiotics about 80 years ago, infectious diseases were the major cause of mortality in humans. Thus, the increased incidence of antibiotic resistance in bacterial pathogens poses a major public health concern. Many pathogens that cause millions of death worldwide and are major agents of food- borne outbreaks, bubonic plague, and secondary hospital infections require the assembly of a bacterial needle-like nanoinjector for pathogenesis. The proposed research seeks to determine how bacteria assemble the nanoinjector by determining the protein-protein interactions of its components. This knowledge is important in designing novel anti-infectives, which will prevent pathogens from invading human cells but will not contribute to the development of antibiotic resistance.
|Dey, Supratim; Anbanandam, Asokan; Mumford, Ben E et al. (2017) Characterization of Small-Molecule Scaffolds That Bind to the Shigella Type?III Secretion System Protein IpaD. ChemMedChem 12:1534-1541|
|Kaur, Kawaljit; Park, Hyewon; Pandey, Nootan et al. (2017) Identification of a new small ubiquitin-like modifier (SUMO)-interacting motif in the E3 ligase PIASy. J Biol Chem 292:10230-10238|
|Kaur, Kawaljit; Wu, Xiaoqing; Fields, James K et al. (2017) The fungal natural product azaphilone-9 binds to HuR and inhibits HuR-RNA interaction in vitro. PLoS One 12:e0175471|
|Kaur, Kawaljit; Chatterjee, Srirupa; De Guzman, Roberto N (2016) Characterization of the Shigella and Salmonella Type?III Secretion System Tip-Translocon Protein-Protein Interaction by Paramagnetic Relaxation Enhancement. Chembiochem 17:745-752|
|McShan, Andrew C; Anbanandam, Asokan; Patnaik, Sikta et al. (2016) Characterization of the Binding of Hydroxyindole, Indoleacetic acid, and Morpholinoaniline to the Salmonella Type?III Secretion System Proteins SipD and SipB. ChemMedChem 11:963-71|
|McShan, Andrew C; Kaur, Kawaljit; Chatterjee, Srirupa et al. (2016) NMR identification of the binding surfaces involved in the Salmonella and Shigella Type III secretion tip-translocon protein-protein interactions. Proteins 84:1097-107|
|Chaudhury, Sukanya; de Azevedo Souza, Clarice; Plano, Gregory V et al. (2015) The LcrG Tip Chaperone Protein of the Yersinia pestis Type III Secretion System Is Partially Folded. J Mol Biol 427:3096-109|
|Chaudhury, Sukanya; Nordhues, Bryce A; Kaur, Kawaljit et al. (2015) Nuclear Magnetic Resonance Characterization of the Type III Secretion System Tip Chaperone Protein PcrG of Pseudomonas aeruginosa. Biochemistry 54:6576-85|
|Lan, Lan; Appelman, Carl; Smith, Amber R et al. (2015) Natural product (-)-gossypol inhibits colon cancer cell growth by targeting RNA-binding protein Musashi-1. Mol Oncol 9:1406-20|
|McShan, Andrew C; De Guzman, Roberto N (2015) The bacterial type III secretion system as a target for developing new antibiotics. Chem Biol Drug Des 85:30-42|
Showing the most recent 10 out of 19 publications