Thursday, October 24, 2019 -
12:00 to 13:00
Specific location: 
Room 201

BMC Semniar Thursday 24 October, 12:00 in Læknagarður Vatnsmýrarvegur 16, room 201

Speaker: Dr. Saiful M Chowdhury, Associate Professor at Department of Chemistry and Biochemistry, the University of Texas at Arlington, Texas, USA.

Title: Toll-like Receptor 2 (TLR2) Interactome by a Novel Cross-linking Proteomics Technology

Abstract: Protein-protein interactions and protein post-translational modifications (PTMs) are the major events which regulate signaling cascades in the cells. Understanding the protein networks in diseased and normal states will provide insight into the physiological and pathological processes of those diseases at a molecular level. The major challenge at this moment is the reliable identification and quantification of protein networks and PTMs in large-scale studies. Mass spectrometry based affinity proteomics is one of the key techniques to study cellular signaling pathways. To improve this procedure, cross-linking is now being employed before affinity and antibody based purification to covalently attach proximal proteins. Cross-linking helped to utilize strong denaturing washing conditions and keep transient and weak interactions attached to the targeted proteins. Interactions can be identified by identifying the proteins only or some cases looking specifically to the cross-linked peptides.

Toll-like receptor 2 (TLR2) is one of the crucial pattern recognition receptor in immune signaling pathways. In order to study TLR2 interactome, we designed a co-immunoprecipitation (Co-IP) based cross-linking proteomics study to decipher the cellular signaling pathways of TLR2 under the sequential treatment of TLR2 ligand and statin drug. A hemagglutinin (HA) tagged TLR2 transfected HEK293 cell line was utilized to identify the TLR2 interactome upon the exposure of lipopeptide, Pam3CSK4 and drug statin. To stabilize protein of proximity, along with the affinity pulldown we utilized two different crosslinkers with different spacer chain lengths. After stringent filtering of data among identified proteins in cross-linked and non cross-linked samples upon the treatment of Pam3CSK4 and statin we identified two proteins as potential new interactors of TLR2.

In this talk, along with a detailed TLR2 interactome study, several chemical proteomics methods will be presented, which can be utilized for identifying large-scale protein-protein interaction networks and lipid modifications of proteins.

Bio: Dr. Saiful M. Chowdhury received his B.Sc. (honors) and M.Sc. degree (first class in both exams) in the Department of Applied Chemistry and Chemical Engineering from University of Dhaka, Dhaka, Bangladesh. He completed another MS in Bio-organic chemistry from Florida International University (FIU), Miami, FL, USA in 2001. He earned his PhD in Bio-analytical Chemistry from Washington State University, Pullman WA, USA under the supervision of Dr. James E. Bruce at 2006.  After finishing his PhD, he joined as a postdoctoral fellow in the world-renowned proteomics and mass spectrometry group of Dr. Richard D. Smith in Pacific Northwest National Laboratory (PNNL), Richland, WA, USA.  In his postdoctoral training in Dr. Richard D. Smith’s group at PNNL, he developed several cutting-edge proteomics tools for global and targeted discovery of protein interactions utilizing tandem affinity tags, chemical cross-linking approaches and mass spectrometry. He worked with the systems biology team at PNNL, and applied these methodologies to investigate protein interactions related to Salmonella pathogenesis and also host-pathogen interactions. From Dec. 2009 - July 2012, he was employed as a research fellow in the laboratory of respiratory biology at the National Institute of Environmental Health Sciences (NIEHS) at National Institute of Health (NIH) and conducted research under the mentorship of Michael B. Fessler MD, head of the host-defense group. At NIEHS, NIH, he studied lipid raft proteome and toll-like receptors (TLRs) signaling using mass spectrometry-based quantitative and chemical proteomics tools.

Dr. Chowdhury joined at the University of Texas at Arlington (UTA) at fall 2012 as an assistant professor and currently a tenured associate professor in the dept. of Chemistry and Biochemistry at UTA. His laboratory focuses on mass spectrometry-based method development for protein-protein interactions and PTMs and its application to study environmental diseases impacted by innate immunity. The focused biological application of his research is to understand comprehensive inflammatory signaling pathways of Toll-like Receptors (TLRs).

Selected publications:

Kamal, A.H.M.; Aloor, Jim J.; Fessler, M. B.; Chowdhury, S.M*.-Cross-linking Proteomics Indicates Effects of Simvastatin on the TLR2 interactome and Reveals ACTR1A as a Novel Regulator of the TLR2 Signal Cascade”-Mol Cell Proteomics. 2019 Sep;18(9):1732-1744.

Perry, B.; Andrew, A.; Kamal, A. H. M.; Card, D.; Schield, D.; Pasquesi, G.; Pellegrino, M.; Mackessy, S.; Chowdhury, S. M*.; Secor, S.; Castoe, T. Multi-species comparisons of snakes suggest that insulin and stress response signaling modulate post-feeding intestinal regeneration. Proc Biol Sci. 2019 Jul 10;286(1906):20190910.

Kamal, A. H. M.; Chakrabarty, J. K.; Udden, S. M. N.; Zaki, M. H.; Chowdhury, S. M*. Inflammatory Proteomic Network Analysis of Statin-treated and Lipopolysaccharide-activated Macrophages. Scientific reports 2018, 8, 164.

Chakrabarty, J. K.; Naik, A. G.; Fessler, M. B.; Munske, G. R.; Chowdhury, S. M*. Differential Tandem Mass Spectrometry-Based Cross-Linker: A New Approach for High Confidence in Identifying Protein Cross-Linking. Analytical chemistry 2016, 88, 10215-10222.

Chowdhury, Saiful M*.; Zhu, Xuewei.; Aloor, Jim J; Azzam, Kathleen M; Gabor, Kristin A; Ge, William; Addo, Kezia A; Tomer, Kenneth B; Parks, John S; Fessler, Michael B; Proteomic analysis of ABCA1-null macrophages reveals a role for stomatin like protein-2 in raft composition and Toll like Receptor signaling. Mol Cell Proteomics. 2015 Jul;14(7):1859-70.


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