Dr. Ching-Ju Tsai

Photo of Ching-Ju Tsai

Research scientist

GPCR signaling :: membrane protein biochemistry

Paul Scherrer Institut
Forschungsstrasse 111
5232 Villigen PSI
Schweiz

G-protein coupled receptors (GPCRs) are the targets of almost half of today’s pharmaceuticals. They contribute to signal transduction across the cell membrane. GPCRs are activated by extracellular stimuli such as light, hormone, and small ligand, resulting in conformational changes and interaction with a number of signalling and regulatory proteins including G proteins, kinases and arrestins. The first step in GPCR activation leads to conformational changes which trigger interaction with G proteins. There are four main subtypes of G proteins, each inducing specific signalling pathways. Most GPCRs can couple to more than one G-protein subtype, and therefore it is fundamental to understand GPCR signalling by studying the coupling specificity between G protein and GPCRs. We aim to decipher the mechanism by which this selectivity is achieved. To do so, we use X-ray crystallography, electron cryo-microscopy (cryo-EM) together with biochemical techniques to characterize the molecular mechanism of GPCR signalling complexes.


  • 2023

  • Ultrafast structural changes direct the first molecular events of visionGruhl T, Weinert T, Rodrigues MJ, Milne CJ, Ortolani G, Nass K, Nango E, Sen S, Johnson PJM, Cirelli C, Furrer A, Mous S, Skopintsev P, James D, Dworkowski F, Båth P, Kekilli D, Ozerov D, Tanaka R, Glover H, Bacellar C, Brünle S, Casadei CM, Diethelm AD, Gashi D, Gotthard G, Guixà-González R, Joti Y, Kabanova V, Knopp G, Lesca E, Ma P, Martiel I, Mühle J, Owada S, Pamula F, Sarabi D, Tejero O, Tsai CJ, Varma N, Wach A, Boutet S, Tono K, Nogly P, Deupi X, Iwata S, Neutze R, Standfuss J, Schertler G, Panneels V
    Nature, 615(7954), 939–944 (2023)
    DOI: 10.1038/s41586-023-05863-6
  • Continuous population-level monitoring of SARS-CoV-2 seroprevalence in a large European metropolitan regionEmmenegger M, De Cecco E, Lamparter D, Jacquat RPB, Riou J, Menges D, Ballouz T, Ebner D, Schneider MM, Morales IC, Doğançay B, Guo J, Wiedmer A, Domange J, Imeri M, Moos R, Zografou C, Batkitar L, Madrigal L, Schneider D, Trevisan C, Gonzalez-Guerra A, Carrella A, Dubach IL, Xu CK, Meisl G, Kosmoliaptsis V, Malinauskas T, Burgess-Brown N, Owens R, Hatch S, Mongkolsapaya J, Screaton GR, Schubert K, Huck JD, Liu F, Pojer F, Lau K, Hacker D, Probst-Müller E, Cervia C, Nilsson J, Boyman O, Saleh L, Spanaus K, von Eckardstein A, Schaer DJ, Ban N, Tsai CJ, Marino J, Schertler GFX, Ebert N, Thiel V, Gottschalk J, Frey BM, Reimann RR, Hornemann S, Ring AM, Knowles TPJ, Puhan MA, Althaus CL, Xenarios I, Stuart DI, Aguzzi A
    iScience, 26(2), 105928 (2023)
    DOI: 10.1016/j.isci.2023.105928
  • 2022

  • Preparation of a stable CCL5·CCR5·Gi signaling complex for Cryo-EM analysisIsaikina P, Tsai CJ, Petrovic I, Rogowski M, Dürr AM, Grzesiek S
    Methods in cell biology, 169, 115–141 (2022)
    DOI: 10.1016/bs.mcb.2022.03.00
  • 2021

  • Versatile microporous polymer-based supports for serial macromolecular crystallographyMartiel I, Beale JH, Karpik A, Huang CY, Vera L, Olieric N, Wranik M, Tsai CJ, Mühle J, Aurelius O, John J, Högbom M, Wang M, Marsh M, Padeste C
    Proceedings of the National Academy of Sciences of the United States of America, 118(31), e2024146118 (2021)
    DOI: 10.1107/S2059798321007324
  • High-mass MALDI-MS unravels ligand-mediated G protein-coupling selectivity to GPCRsWu N, Olechwier AM, Brunner C, Edwards PC, Tsai CJ, Tate CG, Schertler GFX, Schneider G, Deupi X, Zenobi R, Ma P
    Proceedings of the National Academy of Sciences of the United States of America, 118(31), e2024146118 (2021)
    DOI: 10.1073/pnas.2024146118
  • Structural basis of the activation of the CC chemokine receptor 5 by a chemokine agonistIsaikina P, Tsai CJ, Dietz N, Pamula F, Grahl A, Goldie KN, Guixà-González R, Branco C, Paolini-Bertrand M, Calo N, Cerini F, Schertler GFX, Hartley O, Stahlberg H, Maier T, Deupi X, Grzesiek S
    Science advances, 7(25), eabg8685 (2021)
    DOI: 10.1126/sciadv.abg8685
  • Biochemical Characterization of GPCR-G Protein Complex FormationPamula F, Tsai CJ
    Methods in molecular biology (Clifton, N.J.), 2302, 37–48 (2021)
    DOI: 10.1007/978-1-0716-1394-8_3
  • 2020

  • GPCR Activation States Induced by Nanobodies and Mini-G Proteins Compared by NMR SpectroscopyRößler P, Mayer D, Tsai CJ, Veprintsev DB, Schertler GFX, Gossert AD
    Molecules (Basel, Switzerland), 25(24), 5984 (2020)
    DOI: 10.3390/molecules25245984
  • Strategic Screening and Characterization of the Visual GPCR-mini-G Protein Signaling Complex for Successful CrystallizationPamula F, Mühle J, Blanc A, Nehmé R, Edwards PC, Tate CG, Tsai CJ
    Journal of visualized experiments, 157, 10.3791/60747 (2020)
    DOI: 10.3791/60747
  • Membrane Protein CrystallizationTsai CJ, Schertler GFX
    Structural Biology in Drug Discovery: Methods, Techniques, and Practices: 187-210 (2020)
    DOI: 10.1002/9781118681121.ch9
  • 2019

  • Emerging Two-Dimensional Crystallization of Cucurbit[8]uril Complexes: From Supramolecular Polymers to NanofibersBarrio JD, Liu J, Brady RA, Tan CSY, Chiodini S, Ricci M, Fernández-Leiro R, Tsai CJ, Vasileiadi P, Di Michele L, Lairez D, Toprakcioglu C, Scherman OA
    Journal of the American Chemical Society, 141(36), 14021–14025 (2019)
    DOI: 10.1021/jacs.9b07506
  • Cryo-EM structure of the rhodopsin-Gαi-βγ complex reveals binding of the rhodopsin C-terminal tail to the Gβ subunitTsai CJ, Marino J, Adaixo R, Pamula F, Muehle J, Maeda S, Flock T, Taylor NM, Mohammed I, Matile H, Dawson RJ, Deupi X, Stahlberg H, Schertler G
    eLife, 8, e46041 (2019)
    DOI: 10.7554/eLife.46041
  • Structure-factor amplitude reconstruction from serial femtosecond crystallography of two-dimensional membrane-protein crystalsCasadei CM, Nass K, Barty A, Hunter MS, Padeste C, Tsai CJ, Boutet S, Messerschmidt M, Sala L, Williams GJ, Ozerov D, Coleman M, Li XD, Frank M, Pedrini B
    IUCrJ, 6(Pt 1), 34–45 (2019)
    DOI: 10.1107/S2052252518014641
  • 2018

  • Crystal structure of rhodopsin in complex with a mini-G o sheds light on the principles of G protein selectivity Tsai C, Pamula F, Nehmé R, Mühle J, Weinert T, Flock T, Nogly P, Edwards Patricia C, Carpenter B, Gruhl T, Ma P, Deupi X, Standfuss J, Tate Christopher G, Schertler Gebhard FX
    Science advances, 4(9), eaat7052 (2018).
    DOI: 10.1126/sciadv.aat7052
  • Resolution extension by image summing in serial femtosecond crystallography of two-dimensional membrane-protein crystalsCasadei CM, Tsai CJ, Barty A, Hunter MS, Zatsepin NA, Padeste C, Capitani G, Benner WH, Boutet S, Hau-Riege SP, Kupitz C, Messerschmidt M, Ogren JI, Pardini T, Rothschild KJ, Sala L, Segelke B, Williams GJ, Evans JE, Li XD, Coleman M, Pedrini B, Frank M
    IUCrJ, 5(Pt 1), 103–117 (2018).
    DOI: 10.1107/S2052252517017043
  • 2017

  • Structural biology: Signalling under the microscopeTsai CJ, Standfuss J, Glaeser RM
    Nature, 546(7656), 36–37 (2017).
    DOI: 10.1038/nature22491
  • 2016

  • Backbone NMR reveals allosteric signal transduction networks in the beta1-adrenergic receptor Isogai S, Deupi X, Opitz C, Heydenreich FM, Tsai CJ, Brueckner F, Schertler GFX, Veprintsev DB, Grzesiek S
    Nature, 530(7589), 237–241 (2016).
    DOI: 10.1038/nature16577
  • Pre-2015

  • Low-Z polymer sample supports for fixed-target serial femtosecond X-ray crystallography Feld GK, Heymann M, Benner WH, Pardini T, Tsai CJ, Boutet S, Coleman MA, Hunter MS, Li X, Messerschmidt M, Opathalage A, Pedrini B, Williams GJ, Krantz BA, Fraden S, Hau-Riege S, Evans JE, Segelke BW, Frank M
    Journal of Applied Crystallography, 48(4), 1072-1079 (2015).
    DOI: 10.1107/S1600576715010493
  • Time-resolved structural studies with serial crystallography: A new light on retinal proteinsPanneels V, Wu W, Tsai CJ, Nogly P, Rheinberger J, Jaeger K, Cicchetti G, Gati C, Kick LM, Sala L, Capitani G, Milne C, Padeste C, Pedrini B, Li XD, Standfuss J, Abela R, Schertler G
    Structural dynamics (Melville, N.Y.), 2(4), 041718 (2015).
    DOI: 10.1063/1.4922774
  • 7 Å resolution in protein two-dimensional-crystal X-ray diffraction at Linac Coherent Light SourcePedrini B, Tsai CJ, Capitani G, Padeste C, Hunter MS, Zatsepin NA, Barty A, Benner WH, Boutet S, Feld GK, Hau-Riege SP, Kirian RA, Kupitz C, Messerschmitt M, Ogren JI, Pardini T, Segelke B, Williams GJ, Spence JC, Abela R, Coleman M, Evans JE, Schertler GF, Frank M, Li XD
    Philosophical transactions of the Royal Society of London. Series B, Biological sciences, 369(1647), 20130500 (2014).
    DOI: 10.1098/rstb.2013.0500
  • Femtosecond X-ray diffraction from two-dimensional protein crystalsFrank M, Carlson DB, Hunter MS, Williams GJ, Messerschmidt M, Zatsepin NA, Barty A, Benner WH, Chu K, Graf AT, Hau-Riege SP, Kirian RA, Padeste C, Pardini T, Pedrini B, Segelke B, Seibert MM, Spence JC, Tsai CJ, Lane SM, Li XD, Schertler G, Boutet S, Coleman M, Evans JE
    IUCrJ, 1(Pt 2), 95–100 (2014).
    DOI: 10.1107/S2052252514001444
  • Structural interactions between inhibitor and substrate docking sites give insight into mechanisms of human PS1 complexesLi Y, Lu SH, Tsai CJ, Bohm C, Qamar S, Dodd RB, Meadows W, Jeon A, McLeod A, Chen F, Arimon M, Berezovska O, Hyman BT, Tomita T, Iwatsubo T, Johnson CM, Farrer LA, Schmitt-Ulms G, Fraser PE, St George-Hyslop PH
    Structure (London, England : 1993), 22(1), 125–135 (2013).
    DOI: 10.1016/j.str.2013.09.018
  • Two alternative conformations of a voltage-gated sodium channelTsai CJ, Tani K, Irie K, Hiroaki Y, Shimomura T, McMillan DG, Cook GM, Schertler GF, Fujiyoshi Y, Li XD
    Journal of molecular biology, 425(22), 4074–4088 (2013).
    DOI: 10.1016/j.jmb.2013.06.03
  • Structure of β-adrenergic receptorsBrueckner F, Piscitelli CL, Tsai CJ, Standfuss J, Deupi X, Schertler GF
    Methods in enzymology, 520, 117–151 (2013).
    DOI: 10.1016/B978-0-12-391861-1.00006-X
  • Structural asymmetry in a trimeric Na+/betaine symporter, BetP, from Corynebacterium glutamicumTsai CJ, Khafizov K, Hakulinen J, Forrest LR, Forrest LR, Krämer R, Kühlbrandt W, Ziegler C
    Journal of molecular biology, 407(3), 368–381 (2011).
    DOI: 10.1016/j.jmb.2011.01.028
  • Coupling electron cryomicroscopy and X-ray crystallography to understand secondary active transportTsai CJ, Ziegler C
    Journal of molecular biology, 425(22), 4074–4088 (2010).
    DOI: 10.1016/j.sbi.2010.06.005
  • The role of lipids and salts in two-dimensional crystallization of the glycine-betaine transporter BetP from Corynebacterium glutamicumTsai CJ, Ejsing CS, Shevchenko A, Ziegler C
    Journal of structural biology, 160(3), 275–286 (2007).
    DOI: 10.1016/j.jsb.2007.09.008
  • Structure determination of secondary transport proteins by electron crystallography: two-dimensional crystallization of the betaine uptake system BetPTsai CJ, Ziegler C
    Journal of molecular microbiology and biotechnology, 10(2-4), 197–207 (2005).
    DOI: 10.1159/000091565