The Casarotto Group - Biomolecular Interactions

One of the fascinating properties of biological molecules is their remarkable ability to trigger a range of biological responses by adopting distinct three-dimensional structures. The range of structural diversity forms the basis of a wide range of scientific disciplines ranging from molecular recognition and drug design through to protein folding and design. The Biomolecular Structure Laboratory at the JCSMR seeks to carry out research that explores how the structural properties of biological molecules can impact on the biological process involved in health and disease. Through our close ties with biomedical researchers and clinicians at the JCSMR our laboratory is perfectly placed to examine how bioactivity is governed by molecular shape and recognition.

Although the main focus of our research is from a structural perspective, an integrated approach involving complementary techniques such as molecular biology, kinetics and molecular modelling are routinely employed in the laboratory. Research projects currently under investigation relate to a wide range of diseases and applications including cancer, malaria, heart disease, muscular dystrophy and virus-related illnesses such as AIDS and Ross River fever.

Sundararaj, S., Seneviratne, S., Williams, S. J., Enders, A. & Casarotto, M. G. (2021) Structural determinants of the IRF4/DNA homodimeric complex. Nucleic Acids Res 49, 2255-2265, doi:10.1093/nar/gkaa1287.

Tummala P, Rooke M, Dahlstrom JE, Takahashi S, Casarotto MG, Fernando N, Hughes MM, O'Neill LAJ, Board PG (2021). Glutathione Transferase Omega 1 confers protection against azoxymethane-induced colorectal tumour formation. Carcinogenesis, doi:10.1093/carcin/bgab008.

Robinson, K., Culley, D., Waring, S., Lamb, G. D., Easton, C., Casarotto, M. G. and Dulhunty, A. F, (2020) Peptide mimetic compounds can activate or inhibit cardiac and skeletal ryanodine receptors, Life Sciences; In Press

Xie, Y., Tummala, P., Oakley, A. J., Deora, G. S., Nakano, Y., Rooke, M., Cuellar, M. E., Strasser, J. M., Dahlin, J. L., Walters, M. A., Casarotto, M. G., Board, P. G., and Baell, J. B. (2020) Development of Benzenesulfonamide Derivatives as Potent Glutathione Transferase Omega-1 Inhibitors, J Med Chem 63, 2894-2914.

Chiou, P. T., Ohms, S., Board, P. G., Dahlstrom, J. E., Rangasamy, D., and Casarotto, M. G. (2020) Efavirenz as a potential drug for the treatment of triple-negative breast cancers, Clin Transl Oncol., doi: 10.1007/s12094-020-02424-5

Hughes, M. M., Hooftman, A., Angiari, S., Tummala, P., Zaslona, Z., Runtsch, M. C., McGettrick, A. F., Sutton, C. E., Diskin, C., Rooke, M., Takahashi, S., Sundararaj, S., Casarotto, M. G., Dahlstrom, J. E., Palsson-McDermott, E. M., Corr, S. C., Mills, K. H. G., Preston, R. J. S., Neamati, N., Xie, Y., Baell, J. B., Board, P. G., and O'Neill, L. A. J. (2019) Glutathione Transferase Omega-1 Regulates NLRP3 Inflammasome Activation through NEK7 Deglutathionylation, Cell Rep 29, 151-161 e155.

Xie, Y., Dahlin, J. L., Oakley, A. J., Casarotto, M. G., Board, P. G., and Baell, J. B. (2018) Reviewing Hit Discovery Literature for Difficult Targets: Glutathione Transferase Omega-1 as an Example, J Med Chem 61, 7448-7470.

Sundararaj, S., Shishmarev, D., Lin, Y., Aditya, S., and Casarotto, M. G. (2018) (1)H, (13)C and (15)N backbone NMR chemical shift assignments of the C-terminal P4 domain of Ahnak, Biomol NMR Assign 12, 253-257.

Robinson, K., Easton, C. J., Dulhunty, A. F., and Casarotto, M. G. (2018) Exploiting Peptidomimetics to Synthesize Compounds That Activate Ryanodine Receptor Calcium Release Channels, ChemMedChem 13, 1957-1971.

Perez, C. F., Eltit, J. M., Lopez, J. R., Bodnar, D., Dulhunty, A. F., Aditya, S., and Casarotto, M. G. (2018) Functional and structural characterization of a novel malignant hyperthermia-susceptible variant of DHPR-beta1a subunit (CACNB1), Am J Physiol Cell Physiol 314, C323-C333.

Dulhunty, A. F., Beard, N. A., and Casarotto, M. G. (2018) Recent advances in understanding the ryanodine receptor calcium release channels and their role in calcium signalling, F1000Res 7.

Richardson, S. J., Steele, G. A., Gallant, E. M., Lam, A., Schwartz, C. E., Board, P. G., Casarotto, M. G., Beard, N. A., and Dulhunty, A. F. (2017) Association of FK506 binding proteins with RyR channels - effect of CLIC2 binding on sub-conductance opening and FKBP binding, J Cell Sci 130, 3588-3600.

Norris, N. C., Joseph, S., Aditya, S., Karunasekara, Y., Board, P. G., Dulhunty, A. F., Oakley, A. J., and Casarotto, M. G. (2017) Structural and biophysical analyses of the skeletal dihydropyridine receptor beta subunit beta1a reveal critical roles of domain interactions for stability, J Biol Chem 292, 8401-8411.

Menon, D., Innes, A., Oakley, A. J., Dahlstrom, J. E., Jensen, L. M., Brustle, A., Tummala, P., Rooke, M., Casarotto, M. G., Baell, J. B., Nguyen, N., Xie, Y., Cuellar, M., Strasser, J., Dahlin, J. L., Walters, M. A., Burgio, G., O'Neill, L. A. J., and Board, P. G. (2017) GSTO1-1 plays a pro-inflammatory role in models of inflammation, colitis and obesity, Sci Rep 7, 17832.

Dulhunty, A. F., Wei-LaPierre, L., Casarotto, M. G., and Beard, N. A. (2017) Core skeletal muscle ryanodine receptor calcium release complex, Clin Exp Pharmacol Physiol 44, 3-12.

Dulhunty, A. F., Board, P. G., Beard, N. A., and Casarotto, M. G. (2017) Physiology and Pharmacology of Ryanodine Receptor Calcium Release Channels, Adv Pharmacol 79, 287-324.

Rosenberg, M. R., Weaver, L. M., and Casarotto, M. G. (2016) Probing interactions of Vpu from HIV-1 with amiloride-based compounds, Biochim Biophys Acta 1858, 733-739.

Li, J., Hardy, K., Phetsouphanh, C., Tu, W. J., Sutcliffe, E. L., McCuaig, R., Sutton, C. R., Zafar, A., Munier, C. M., Zaunders, J. J., Xu, Y., Theodoratos, A., Tan, A., Lim, P. S., Knaute, T., Masch, A., Zerweck, J., Brezar, V., Milburn, P. J., Dunn, J., Casarotto, M. G., Turner, S. J., Seddiki, N., Kelleher, A. D., and Rao, S. (2016) Nuclear PKC-theta facilitates rapid transcriptional responses in human memory CD4+ T cells through p65 and H2B phosphorylation, J Cell Sci 129, 2448-2461.

Hewawasam, R. P., Liu, D., Casarotto, M. G., Board, P. G., and Dulhunty, A. F. (2016) The GSTM2 C-Terminal Domain Depresses Contractility and Ca2+ Transients in Neonatal Rat Ventricular Cardiomyocytes, PLoS One 11, e0162415.

Samarasinghe, K., Liu, D., Tummala, P., Cappello, J., Pace, S. M., Arnolda, L., Casarotto, M. G., Dulhunty, A. F., and Board, P. G. (2015) Glutathione transferase M2 variants inhibit ryanodine receptor function in adult mouse cardiomyocytes, Biochem Pharmacol 97, 269-280.

Rebbeck, R. T., Willemse, H., Groom, L., Casarotto, M. G., Board, P. G., Beard, N. A., Dirksen, R. T., and Dulhunty, A. F. (2015) Regions of ryanodine receptors that influence activation by the dihydropyridine receptor beta1a subunit, Skelet Muscle 5, 23.

Rebbeck, R. T., Karunasekara, Y., Board, P. G., Beard, N. A., Casarotto, M. G., and Dulhunty, A. F. (2014) Skeletal muscle excitation-contraction coupling: who are the dancing partners?, Int J Biochem Cell Biol 48, 28-38.

Ellyard, J. I., Jerjen, R., Martin, J. L., Lee, A. Y., Field, M. A., Jiang, S. H., Cappello, J., Naumann, S. K., Andrews, T. D., Scott, H. S., Casarotto, M. G., Goodnow, C. C., Chaitow, J., Pascual, V., Hertzog, P., Alexander, S. I., Cook, M. C., and Vinuesa, C. G. (2014) Identification of a pathogenic variant in TREX1 in early-onset cerebral systemic lupus erythematosus by Whole-exome sequencing, Arthritis Rheumatol 66, 3382-3386.

Zhao, X., Jie, Y., Rosenberg, M. R., Wan, J., Zeng, S., Cui, W., Xiao, Y., Li, Z., Tu, Z., Casarotto, M. G., and Hu, W. (2012) Design and synthesis of pinanamine derivatives as anti-influenza A M2 ion channel inhibitors, Antiviral Res 96, 91-99.

Sutcliffe, E. L., Li, J., Zafar, A., Hardy, K., Ghildyal, R., McCuaig, R., Norris, N. C., Lim, P. S., Milburn, P. J., Casarotto, M. G., Denyer, G., and Rao, S. (2012) Chromatinized Protein Kinase C-theta: Can It Escape the Clutches of NF-kappaB?, Front Immunol 3, 260.

Seymour, V. A., Curmi, J. P., Howitt, S. M., Casarotto, M. G., Laver, D. R., and Tierney, M. L. (2012) Selective modulation of different GABAA receptor isoforms by diazepam and etomidate in hippocampal neurons, Int J Biochem Cell Biol 44, 1491-1500.

Liu, D., Hewawasam, R., Karunasekara, Y., Casarotto, M. G., Dulhunty, A. F., and Board, P. G. (2012) The inhibitory glutathione transferase M2-2 binding site is located in divergent region 3 of the cardiac ryanodine receptor, Biochem Pharmacol 83, 1523-1529.

Karunasekara, Y., Rebbeck, R. T., Weaver, L. M., Board, P. G., Dulhunty, A. F., and Casarotto, M. G. (2012) An alpha-helical C-terminal tail segment of the skeletal L-type Ca2+ channel beta1a subunit activates ryanodine receptor type 1 via a hydrophobic surface, FASEB J 26, 5049-5059.

Zhou, H., Brock, J., Casarotto, M. G., Oakley, A. J., and Board, P. G. (2011) Novel folding and stability defects cause a deficiency of human glutathione transferase omega 1, J Biol Chem 286, 4271-4279.

Tae, H. S., Cui, Y., Karunasekara, Y., Board, P. G., Dulhunty, A. F., and Casarotto, M. G. (2011) Cyclization of the intrinsically disordered alpha1S dihydropyridine receptor II-III loop enhances secondary structure and in vitro function, J Biol Chem 286, 22589-22599.

Tae, H., Wei, L., Willemse, H., Mirza, S., Gallant, E. M., Board, P. G., Dirksen, R. T., Casarotto, M. G., and Dulhunty, A. (2011) The elusive role of the SPRY2 domain in RyR1, Channels (Austin) 5, 148-160.

Rebbeck, R. T., Karunasekara, Y., Gallant, E. M., Board, P. G., Beard, N. A., Casarotto, M. G., and Dulhunty, A. F. (2011) The beta(1a) subunit of the skeletal DHPR binds to skeletal RyR1 and activates the channel via its 35-residue C-terminal tail, Biophys J 100, 922-930.

Peralvarez-Marin, A., Tae, H., Board, P. G., Casarotto, M. G., Dulhunty, A. F., and Samso, M. (2011) 3D Mapping of the SPRY2 domain of ryanodine receptor 1 by single-particle cryo-EM, PLoS One 6, e25813.

Morris, M. J., Liu, D., Weaver, L. M., Board, P. G., and Casarotto, M. G. (2011) A structural basis for cellular uptake of GST-fold proteins, PLoS One 6, e17864.

Dulhunty, A. F., Hewawasam, R., Liu, D., Casarotto, M. G., and Board, P. G. (2011) Regulation of the cardiac muscle ryanodine receptor by glutathione transferases, Drug Metab Rev 43, 236-252.

Dulhunty, A. F., Casarotto, M. G., and Beard, N. A. (2011) The ryanodine receptor: a pivotal Ca2+ regulatory protein and potential therapeutic drug target, Curr Drug Targets 12, 709-723.

Rosenberg, M. R., and Casarotto, M. G. (2010) Coexistence of two adamantane binding sites in the influenza A M2 ion channel, Proc Natl Acad Sci U S A 107, 13866-13871.

Hewawasam, R., Liu, D., Casarotto, M. G., Dulhunty, A. F., and Board, P. G. (2010) The structure of the C-terminal helical bundle in glutathione transferase M2-2 determines its ability to inhibit the cardiac ryanodine receptor, Biochem Pharmacol 80, 381-388.

Tae, H. S., Norris, N. C., Cui, Y., Karunasekara, Y., Board, P. G., Dulhunty, A. F., and Casarotto, M. G. (2009) Molecular recognition of the disordered dihydropyridine receptor II-III loop by a conserved spry domain of the type 1 ryanodine receptor, Clin Exp Pharmacol Physiol 36, 346-349.

Tae, H., Casarotto, M. G., and Dulhunty, A. F. (2009) Ubiquitous SPRY domains and their role in the skeletal type ryanodine receptor, Eur Biophys J 39, 51-59.

Morris, M. J., Craig, S. J., Sutherland, T. M., Board, P. G., and Casarotto, M. G. (2009) Transport of glutathione transferase-fold structured proteins into living cells, Biochim Biophys Acta 1788, 676-685.

Liu, D., Hewawasam, R., Pace, S. M., Gallant, E. M., Casarotto, M. G., Dulhunty, A. F., and Board, P. G. (2009) Dissection of the inhibition of cardiac ryanodine receptors by human glutathione transferase GSTM2-2, Biochem Pharmacol 77, 1181-1193.

Kimura, T., Lueck, J. D., Harvey, P. J., Pace, S. M., Ikemoto, N., Casarotto, M. G., Dirksen, R. T., and Dulhunty, A. F. (2009) Alternative splicing of RyR1 alters the efficacy of skeletal EC coupling, Cell Calcium 45, 264-274.

Karunasekara, Y., Dulhunty, A. F., and Casarotto, M. G. (2009) The voltage-gated calcium-channel beta subunit: more than just an accessory, Eur Biophys J 39, 75-81.

Cui, Y., Tae, H. S., Norris, N. C., Karunasekara, Y., Pouliquin, P., Board, P. G., Dulhunty, A. F., and Casarotto, M. G. (2009) A dihydropyridine receptor alpha1s loop region critical for skeletal muscle contraction is intrinsically unstructured and binds to a SPRY domain of the type 1 ryanodine receptor, Int J Biochem Cell Biol 41, 677-686.

Dulhunty, A. F., Beard, N. A., Pouliquin, P., and Casarotto, M. G. (2007) Agonists and antagonists of the cardiac ryanodine receptor: potential therapeutic agents?, Pharmacol Ther 113, 247-263.

Bannister, M. L., Hamada, T., Murayama, T., Harvey, P. J., Casarotto, M. G., Dulhunty, A. F., and Ikemoto, N. (2007) Malignant hyperthermia mutation sites in the Leu2442-Pro2477 (DP4) region of RyR1 (ryanodine receptor 1) are clustered in a structurally and functionally definable area, Biochem J 401, 333-339.

Pouliquin, P., Pace, S. M., Curtis, S. M., Harvey, P. J., Gallant, E. M., Zorzato, F., Casarotto, M. G., and Dulhunty, A. F. (2006) Effects of an alpha-helical ryanodine receptor C-terminal tail peptide on ryanodine receptor activity: modulation by Homer, Int J Biochem Cell Biol 38, 1700-1715.

Casarotto, M. G., Cui, Y., Karunasekara, Y., Harvey, P. J., Norris, N., Board, P. G., and Dulhunty, A. F. (2006) Structural and functional characterization of interactions between the dihydropyridine receptor II-III loop and the ryanodine receptor, Clin Exp Pharmacol Physiol 33, 1114-1117.

Dulhunty, A. F., Karunasekara, Y., Curtis, S. M., Harvey, P. J., Board, P. G., and Casarotto, M. G. (2005) The recombinant dihydropyridine receptor II-III loop and partly structured 'C' region peptides modify cardiac ryanodine receptor activity, Biochem J 385, 803-813.

Dulhunty, A. F., Karunasekara, Y., Curtis, S. M., Harvey, P. J., Board, P. G., and Casarotto, M. G. (2005) Role of some unconserved residues in the "C" region of the skeletal DHPR II-III loop, Front Biosci 10, 1368-1381.

Dulhunty, A. F., Cengia, L., Young, J., Pace, S. M., Harvey, P. J., Lamb, G. D., Chan, Y. N., Wimmer, N., Toth, I., and Casarotto, M. G. (2005) Functional implications of modifying RyR-activating peptides for membrane permeability, Br J Pharmacol 144, 743-754.

Cui, Y., Karunasekara, Y., Harvey, P. J., Board, P. G., Dulhunty, A. F., and Casarotto, M. G. (2005) 1H, 13C and 15N assignments for the II-III loop region of the skeletal dyhydropyridine receptor, J Biomol NMR 32, 89-90.

Beard, N. A., Casarotto, M. G., Wei, L., Varsanyi, M., Laver, D. R., and Dulhunty, A. F. (2005) Regulation of ryanodine receptors by calsequestrin: effect of high luminal Ca2+ and phosphorylation, Biophys J 88, 3444-3454.

Tetlow, N., Coggan, M., Casarotto, M. G., and Board, P. G. (2004) Functional polymorphism of human glutathione transferase A3: effects on xenobiotic metabolism and steroid biosynthesis, Pharmacogenetics 14, 657-663.

Dulhunty, A. F., Curtis, S. M., Watson, S., Cengia, L., and Casarotto, M. G. (2004) Multiple actions of imperatoxin A on ryanodine receptors: interactions with the II-III loop "A" fragment, J Biol Chem 279, 11853-11862.

Dulhunty, A. F., Curtis, S. M., Cengia, L., Sakowska, M., and Casarotto, M. G. (2004) Peptide fragments of the dihydropyridine receptor can modulate cardiac ryanodine receptor channel activity and sarcoplasmic reticulum Ca2+ release, Biochem J 379, 161-172.

Casarotto, M. G., Green, D., Pace, S., Young, J., and Dulhunty, A. F. (2004) Activating the ryanodine receptor with dihydropyridine receptor II-III loop segments: size and charge do matter, Front Biosci 9, 2860-2872.

Haarmann, C. S., Green, D., Casarotto, M. G., Laver, D. R., and Dulhunty, A. F. (2003) The random-coil 'C' fragment of the dihydropyridine receptor II-III loop can activate or inhibit native skeletal ryanodine receptors, Biochem J 372, 305-316.

Green, D., Pace, S., Curtis, S. M., Sakowska, M., Lamb, G. D., Dulhunty, A. F., and Casarotto, M. G. (2003) The three-dimensional structural surface of two beta-sheet scorpion toxins mimics that of an alpha-helical dihydropyridine receptor segment, Biochem J 370, 517-527.

Dulhunty, A. F., Haarmann, C. S., Green, D., Laver, D. R., Board, P. G., and Casarotto, M. G. (2002) Interactions between dihydropyridine receptors and ryanodine receptors in striated muscle, Prog Biophys Mol Biol 79, 45-75.

Zuegg, J., Webb, D. C., Foster, P. S., and Casarotto, M. G. (2001) Structural model of human IL-13 defines the spatial interactions with the IL-13Ralpha/IL-4Ralpha receptor, Immunol Cell Biol 79, 332-339.

Casarotto, M. G., Green, D., Pace, S. M., Curtis, S. M., and Dulhunty, A. F. (2001) Structural determinants for activation or inhibition of ryanodine receptors by basic residues in the dihydropyridine receptor II-III loop, Biophys J 80, 2715-2726.

Casarotto, M. G., and Craik, D. J. (2001) Ring flexibility within tricyclic antidepressant drugs, J Pharm Sci 90, 713-721.

Flanagan JU, Chelvanayagam G, Casarotto MG, Parker MW, Board PG (2000). A mutagenic analysis of the role of Arg-107 and Trp-115 in the human Theta class glutathione GSTT2-2. Clinical Chemistry and Enzymology Communications 8, 261-269.

Casarotto, M. G., Gibson, F., Pace, S. M., Curtis, S. M., Mulcair, M., and Dulhunty, A. F. (2000) A structural requirement for activation of skeletal ryanodine receptors by peptides of the dihydropyridine receptor II-III loop, J Biol Chem 275, 11631-11637.

Dulhunty, A. F., Laver, D. R., Gallant, E. M., Casarotto, M. G., Pace, S. M., and Curtis, S. (1999) Activation and inhibition of skeletal RyR channels by a part of the skeletal DHPR II-III loop: effects of DHPR Ser687 and FKBP12, Biophys J 77, 189-203.

Casarotto, M. G., Basran, J., Badii, R., Sze, K. H., and Roberts, G. C. (1999) Direct measurement of the pKa of aspartic acid 26 in Lactobacillus casei dihydrofolate reductase: implications for the catalytic mechanism, Biochemistry 38, 8038-8044.

Birdsall, B., Casarotto, M. G., Cheung, H. T., Basran, J., Roberts, G. C., and Feeney, J. (1997) The influence of aspartate 26 on the tautomeric forms of folate bound to Lactobacillus casei dihydrofolate reductase, FEBS Lett 402, 157-161.

Basran, J., Casarotto, M. G., Basran, A., and Roberts, G. C. (1997) Effects of single-residue substitutions on negative cooperativity in ligand binding to dihydrofolate reductase, Protein Eng 10, 815-826.

Basran, J., Casarotto, M. G., Barsukov, I. L., and Roberts, G. C. (1995) Role of the active-site carboxylate in dihydrofolate reductase: kinetic and spectroscopic studies of the aspartate 26-->asparagine mutant of the Lactobacillus casei enzyme, Biochemistry 34, 2872-2882.

Badii, R., Basran, J., Casarotto, M. G., and Roberts, G. C. (1995) High-level expression and isotopic labeling of Lactobacillus casei dihydrofolate reductase for nuclear magnetic resonance spectroscopy, Protein Expr Purif 6, 237-243.

Casarotto MG, Craik DJ. Solution dynamics of imipramine and amitriptyline in phospholipid vesicles as studied by 1H and 13C NMR. J. Colloid Interface Sci. 158, 326-332 (1993).

Casarotto MG, Craik DJ. 13C and 1H NMR studies of the interaction of tricyclic antidepressant drugs with dodecyldimethylammonium chloride micelles. J. Phys. Chem. 96, 3146-3151 (1992).

Casarotto MG, Craik DJ. 13C and 1H NMR studies of the interaction of tricyclic antidepressant drugs with micellar aggregates. J. Phys. Chem. 95, 7093-7099 (1991).

Casarotto, M. G., Craik, D. J., Lloyd, E. J., and Partridge, A. C. (1991) An NMR and theoretical study of the conformation and internal flexibility of butaclamol hydrochloride, J Med Chem 34, 2036-2043.

Casarotto, M. G., Craik, D. J., and Lloyd, E. J. (1991) NMR studies of the conformational interconversion of butaclamol in solution, J Med Chem 34, 2043-2049.

Casarotto M. G., Craik D. J., Munro S. L. A. (1990) 13C NMR studies of the solution dynamics of tricyclic antidepressants. Magn. Reson. Chem. 28, 533-540.

Smith GJ, Casarotto MG. (1988) Transient species produced by flash photolysis of acid solutions of methylene blue. J. Chem. Soc., Faraday Trans. 2 84, 1803-1807.

Casarotto MG, Smith GJ. (1987) Methylene-blue-sensitized photo-oxidation of terpenes. J. Photochem. Photobiol. A: Chemistry 40, 89-91.