I received my PhD from The University of Helsinki (UH), Finland, in 2014 where I studied molecular mechanisms of endoplasmic reticulum morphogenesis and dynamics in the laboratory of Adjunct Professor Eija Jokitalo at the Institute of Biotechnology (IB) using advanced imaging techniques. After graduation, I did a short postdoctoral training in the Nuclear Actin Lab (IB/UH) lead by Dr Maria Vartianen and, in 2015, I relocated to The University of Queensland (UQ), Brisbane, Australia. During my postdoctoral training at the Queensland Brain Institute (QBI) at UQ, and changed my research field from basic cell biology to neuroscience and super-resolution imaging. I was awarded a 3-year Academy of Finland Postdoctoral Fellowship (2016) and an ARC DECRA Award (2019) to study the role of a lipid modifying enzyme on neuronal function. In 2022, I became a UQ Amplify Fellow and Group Leader in a joint Australian Institute for Bioengineering and Nanotechnology (AIBN) and QBI position at UQ. My lab aims to understand the role of proteins and lipids in neuronal function and dysfunction, as well as mechanisms of neuroparalysis and viral infections.
My laboratory focuses on how lipids and proteins affect cellular and neuronal membrane trafficking, and how neurotoxins and viruses exploit cellular endocytic machinery to gain access into cells. We use in vitro cell and primary neuron cultures as our main model system, allowing us to address the effects of pharmacological perturbations and genetic disease conditions on cellular functions. My team uses a combination of imaging techniques, including electron microscopy, confocal imaging and live-cell super-resolution microscopy, as well as molecular approaches, to understand how cells function in health and disease, which is critical for discovering novel therapeutic strategies for the treatment of disease, viral infections and neurointoxication pathologies.
Journal Article: Synapsin 2a tetramerisation selectively controls the presynaptic nanoscale organisation of reserve synaptic vesicles
Longfield, Shanley F., Gormal, Rachel S., Feller, Matis, Parutto, Pierre, Reingruber, Jürgen, Wallis, Tristan P., Joensuu, Merja, Augustine, George J., Martínez-Mármol, Ramón, Holcman, David and Meunier, Frédéric A. (2024). Synapsin 2a tetramerisation selectively controls the presynaptic nanoscale organisation of reserve synaptic vesicles. Nature Communications, 15 (1) 2217, 1-18. doi: 10.1038/s41467-024-46256-1
Journal Article: The DDHD2-STXBP1 interaction mediates long-term memory via generation of saturated free fatty acids
Akefe, Isaac O, Saber, Saber H, Matthews, Benjamin, Venkatesh, Bharat G, Gormal, Rachel S, Blackmore, Daniel G, Alexander, Suzy, Sieriecki, Emma, Gambin, Yann, Bertran-Gonzalez, Jesus, Vitale, Nicolas, Humeau, Yann, Gaudin, Arnaud, Ellis, Sevannah A, Michaels, Alysee A, Xue, Mingshan, Cravatt, Benjamin, Joensuu, Merja, Wallis, Tristan P and Meunier, Frédéric A (2024). The DDHD2-STXBP1 interaction mediates long-term memory via generation of saturated free fatty acids. The EMBO Journal, 43 (4), 1-35. doi: 10.1038/s44318-024-00030-7
Journal Article: Dissection of alpha‐synuclein specific synaptic functions by gene editing
Madhivanan, Kayalvizhi, Parra‐Rivas, Leonardo A, Joensuu, Merja, Sanders, Shanley, Caballero‐Florán, René, Bingham, Dominic, Sharma, Rohan, Jenkins, Paul M, Leterrier, Christophe, Meunier, Frederic A and Roy, Subhojit (2023). Dissection of alpha‐synuclein specific synaptic functions by gene editing. Alzheimer's & Dementia, 19 (S24). doi: 10.1002/alz.082510
(2020–2023) RL Cooper Medical Research Foundation Limited
Dynamic and molecular determinants of nanoscale organization of different synaptic vesicle pools
(2020) UQ Early Career Researcher
A novel role for saturated fatty acids in learning and memory
(2019–2022) ARC Discovery Early Career Researcher Award
Secretory pathway membrane trafficking and lipid metabolism in health and disease
Doctor Philosophy
The role of saturated free fatty acids in learning and memory
Doctor Philosophy
(2022) Doctor Philosophy
Small, Christopher, Martínez-Mármol, Ramon, Amor, Rumelo, Meunier, Frederic A. and Joensuu, Merja (2021). Combining single molecule super-resolution imaging techniques to unravel the nanoscale organization of the presynapse. Exocytosis and endocytosis: methods and protocols. (pp. 265-286) edited by Florence Niedergang, Nicolas Vitale and Stéphane Gasman. New York, NY, United States: Humana Press. doi: 10.1007/978-1-0716-1044-2_18
Single-molecule imaging of recycling synaptic vesicles in live neurons
Joensuu, Merja, Martínez-Mármol, Ramon, Mollazade, Mahdie, Padmanabhan, Pranesh and Meunier, Frédéric A. (2020). Single-molecule imaging of recycling synaptic vesicles in live neurons. Single molecule microscopy in neurobiology. (pp. 81-114) edited by Nobuhiko Yamamoto and Yasushi Okada. New York, NY United States: Humana Press. doi: 10.1007/978-1-0716-0532-5_5
Longfield, Shanley F., Gormal, Rachel S., Feller, Matis, Parutto, Pierre, Reingruber, Jürgen, Wallis, Tristan P., Joensuu, Merja, Augustine, George J., Martínez-Mármol, Ramón, Holcman, David and Meunier, Frédéric A. (2024). Synapsin 2a tetramerisation selectively controls the presynaptic nanoscale organisation of reserve synaptic vesicles. Nature Communications, 15 (1) 2217, 1-18. doi: 10.1038/s41467-024-46256-1
The DDHD2-STXBP1 interaction mediates long-term memory via generation of saturated free fatty acids
Akefe, Isaac O, Saber, Saber H, Matthews, Benjamin, Venkatesh, Bharat G, Gormal, Rachel S, Blackmore, Daniel G, Alexander, Suzy, Sieriecki, Emma, Gambin, Yann, Bertran-Gonzalez, Jesus, Vitale, Nicolas, Humeau, Yann, Gaudin, Arnaud, Ellis, Sevannah A, Michaels, Alysee A, Xue, Mingshan, Cravatt, Benjamin, Joensuu, Merja, Wallis, Tristan P and Meunier, Frédéric A (2024). The DDHD2-STXBP1 interaction mediates long-term memory via generation of saturated free fatty acids. The EMBO Journal, 43 (4), 1-35. doi: 10.1038/s44318-024-00030-7
Dissection of alpha‐synuclein specific synaptic functions by gene editing
Madhivanan, Kayalvizhi, Parra‐Rivas, Leonardo A, Joensuu, Merja, Sanders, Shanley, Caballero‐Florán, René, Bingham, Dominic, Sharma, Rohan, Jenkins, Paul M, Leterrier, Christophe, Meunier, Frederic A and Roy, Subhojit (2023). Dissection of alpha‐synuclein specific synaptic functions by gene editing. Alzheimer's & Dementia, 19 (S24). doi: 10.1002/alz.082510
Longfield, Shanley F., Mollazade, Mahdie, Wallis, Tristan P., Gormal, Rachel S., Joensuu, Merja, Wark, Jesse R., van Waardenberg, Ashley J., Small, Christopher, Graham, Mark E., Meunier, Frédéric A. and Martínez-Mármol, Ramón (2023). Tau forms synaptic nano-biomolecular condensates controlling the dynamic clustering of recycling synaptic vesicles. Nature Communications, 14 (1) 7277, 1-20. doi: 10.1038/s41467-023-43130-4
Super-resolved trajectory-derived nanoclustering analysis using spatiotemporal indexing
Wallis, Tristan P., Jiang, Anmin, Young, Kyle, Hou, Huiyi, Kudo, Kye, McCann, Alex J., Durisic, Nela, Joensuu, Merja, Oelz, Dietmar, Nguyen, Hien, Gormal, Rachel S. and Meunier, Frédéric A. (2023). Super-resolved trajectory-derived nanoclustering analysis using spatiotemporal indexing. Nature Communications, 14 (1) 3353, 1-16. doi: 10.1038/s41467-023-38866-y
Joensuu, Merja, Syed, Parnayan, Saber, Saber H., Lanoue, Vanessa, Wallis, Tristan P., Rae, James, Blum, Ailisa, Gormal, Rachel S., Small, Christopher, Sanders, Shanley, Jiang, Anmin, Mahrhold, Stefan, Krez, Nadja, Cousin, Michael A., Cooper‐White, Ruby, Cooper‐White, Justin J., Collins, Brett M., Parton, Robert G., Balistreri, Giuseppe, Rummel, Andreas and Meunier, Frédéric A. (2023). Presynaptic targeting of botulinum neurotoxin type A requires a tripartite PSG‐Syt1 ‐ SV2 plasma membrane nanocluster for synaptic vesicle entry. The EMBO Journal, 42 (13) e112095, e112095. doi: 10.15252/embj.2022112095
Kettunen, Pinja, Lesnikova, Angelina, Räsänen, Noora, Ojha, Ravi, Palmunen, Leena, Laakso, Markku, Lehtonen, Šárka, Kuusisto, Johanna, Pietiläinen, Olli, Saber, Saber H., Joensuu, Merja, Vapalahti, Olli P., Koistinaho, Jari, Rolova, Taisia and Balistreri, Giuseppe (2023). SARS-CoV-2 infection of human neurons is TMPRSS2 independent, requires endosomal cell entry, and can be blocked by inhibitors of host phosphoinositol-5 kinase. Journal of Virology, 97 (4), e0014423. doi: 10.1128/jvi.00144-23
Zhu, Yanshan, Chew, Keng Yih, Wu, Melanie, Karawita, Anjana C., McCallum, Georgina, Steele, Lauren E., Yamamoto, Ayaho, Labzin, Larisa I., Yarlagadda, Tejasri, Khromykh, Alexander A., Wang, Xiaohui, Sng, Julian D. J., Stocks, Claudia J., Xia, Yao, Kollmann, Tobias R., Martino, David, Joensuu, Merja, Meunier, Frédéric A., Balistreri, Giuseppe, Bielefeldt-Ohmann, Helle, Bowen, Asha C., Kicic, Anthony, Sly, Peter D., Spann, Kirsten M. and Short, Kirsty R. (2022). Ancestral SARS-CoV-2, but not Omicron, replicates less efficiently in primary pediatric nasal epithelial cells. PLoS Biology, 20 (8) e3001728, 1-19. doi: 10.1371/journal.pbio.3001728
Gormal, Rachel S., Padmanabhan, Pranesh, Kasula, Ravikiran, Bademosi, Adekunle T., Coakley, Sean, Giacomotto, Jean, Blum, Ailisa, Joensuu, Merja, Wallis, Tristan P., Lo, Harriet P., Budnar, Srikanth, Rae, James, Ferguson, Charles, Bastiani, Michele, Thomas, Walter G., Pardon, Els, Steyaert, Jan, Yap, Alpha S., Goodhill, Geoffrey J., Hilliard, Massimo A., Parton, Robert G. and Meunier, Frédéric A. (2020). Modular transient nanoclustering of activated β2-adrenergic receptors revealed by single-molecule tracking of conformation-specific nanobodies. Proceedings of the National Academy of Sciences of the United States of America, 117 (48), 30476-30487. doi: 10.1073/pnas.2007443117
Neuropilin-1 facilitates SARS-CoV-2 cell entry and infectivity
Cantuti-Castelvetri, Ludovico, Ojha, Ravi, Pedro, Liliana D., Djannatian, Minou, Franz, Jonas, Kuivanen, Suvi, van der Meer, Franziska, Kallio, Katri, Kaya, Tuğberk, Anastasina, Maria, Smura, Teemu, Levanov, Lev, Szirovicza, Leonora, Tobi, Allan, Kallio-Kokko, Hannimari, Österlund, Pamela, Joensuu, Merja, Meunier, Frédéric A., Butcher, Sarah J., Winkler, Martin Sebastian, Mollenhauer, Brit, Helenius, Ari, Gokce, Ozgun, Teesalu, Tambet, Hepojoki, Jussi, Vapalahti, Olli, Stadelmann, Christine, Balistreri, Giuseppe and Simons, Mikael (2020). Neuropilin-1 facilitates SARS-CoV-2 cell entry and infectivity. Science, 370 (6518) abd2985, 856-860. doi: 10.1126/science.abd2985
Radial contractility of actomyosin rings facilitates axonal trafficking and structural stability
Wang, Tong, Li, Wei, Martin, Sally, Papadopulos, Andreas, Joensuu, Merja, Liu, Chunxia, Jiang, Anmin, Shamsollahi, Golnoosh, Amor, Rumelo, Lanoue, Vanessa, Padmanabhan, Pranesh and Meunier, Frédéric A. (2020). Radial contractility of actomyosin rings facilitates axonal trafficking and structural stability. Journal of Cell Biology, 219 (5) e201902001, 1-S7. doi: 10.1083/jcb.201902001
Phospholipases in neuronal function: a role in learning and memory?
Joensuu, Merja, Wallis, Tristan P., Saber, Saber H. and Meunier, Frédéric A. (2019). Phospholipases in neuronal function: a role in learning and memory?. Journal of Neurochemistry, 153 (3) jnc.14918, e14918-333. doi: 10.1111/jnc.14918
Witkos, Tomasz M., Chan, Wing Lee, Joensuu, Merja, Rhiel, Manuel, Pallister, Ed, Thomas-Oates, Jane, Mould, A. Paul, Mironov, Alex A., Biot, Christophe, Guerardel, Yann, Morelle, Willy, Ungar, Daniel, Wieland, Felix T., Jokitalo, Eija, Tassabehji, May, Kornak, Uwe and Lowe, Martin (2019). GORAB scaffolds COPI at the trans-Golgi for efficient enzyme recycling and correct protein glycosylation. Nature Communications, 10 (1) 127, 127. doi: 10.1038/s41467-018-08044-6
Kasula, Ravikiran, Blum, Ailisa, Salla-Martret, Merce, Chai, Ye Jin, Jiang, Anmin, Wallis, Tristan P., Gormal, Rachel S., Brouillet, Julie Z., Padmanabhan, Pranesh, Weeratunga, Saroja K., Livingstone, Emma K., Mollazade, Mahdie, Joensuu, Merja, Martínez-Mármol, Ramón, Collins, Brett M. and Meunier, Frederic (2019). VAMP2 Binding to Munc18-1 Domain 3a Controls the Nanoscale Reorganization of the Plasma Membrane and Vesicle Interface During Vesicular Priming. SSRN Electronic Journal. doi: 10.2139/ssrn.3362260
Dendritic spine actin cytoskeleton in autism spectrum disorder
Joensuu, Merja, Lanoue, Vanessa and Hotulainen, Pirta (2018). Dendritic spine actin cytoskeleton in autism spectrum disorder. Progress in Neuro-Psychopharmacology and Biological Psychiatry, 84 (Pt B), 362-381. doi: 10.1016/j.pnpbp.2017.08.023
Joensuu, Merja, Martinez-Marmol, Ramon, Padmanabhan, Pranesh, Glass, Nick R., Durisic, Nela, Pelekanos, Matthew, Mollazade, Mahdie, Balistreri, Giuseppe, Amor, Rumelo, Cooper-White, Justin J., Goodhill, Geoffrey J. and Meunier, Frederic A. (2017). Visualizing endocytic recycling and trafficking in live neurons by subdiffractional tracking of internalized molecules. Nature Protocols, 12 (12), 2590-2622. doi: 10.1038/nprot.2017.116
Joensuu, Merja, Padmanabhan, Pranesh, Durisic, Nela, Bademosi, Adekunle T. D., Cooper-Williams, Elizabeth, Morrow, Isabel C., Harper, Callista B., Jung, WooRam, Parton, Robert G., Goodhill, Geoffrey J., Papadopulos, Andreas and Meunier, Frederic A. (2016). Subdiffractional tracking of internalized molecules reveals heterogeneous motion states of synaptic vesicles. Journal of Cell Biology, 215 (2), 277-292. doi: 10.1083/jcb.201604001
Ramo, Olli, Kumar, Darshan, Gucciardo, Erika, Joensuu, Merja, Saarekas, Maiju, Vihinen, Helena, Belevich, Ilya, Smolander, Olli-Pekka, Qian, Kui, Auvinen, Petri and Jokitalo, Eija (2016). NOGO-A/RTN4A and NOGO-B/RTN4B are simultaneously expressed in epithelial, fibroblast and neuronal cells and maintain ER morphology. Scientific Reports, 6 (1) 35969. doi: 10.1038/srep35969
Microscopy image browser: a platform for segmentation and analysis of multidimensional datasets
Belevich, Ilya, Joensuu, Merja, Kumar, Darshan, Vihinen, Helena and Jokitalo, Eija (2016). Microscopy image browser: a platform for segmentation and analysis of multidimensional datasets. PLoS Biology, 14 (1) e1002340, e1002340. doi: 10.1371/journal.pbio.1002340
ER sheet-tubule balance is regulated by an array of actin filaments and microtubules
Joensuu, Merja and Jokitalo, Eija (2015). ER sheet-tubule balance is regulated by an array of actin filaments and microtubules. Experimental Cell Research, 337 (2), 170-178. doi: 10.1016/j.yexcr.2015.04.009
Genome-wide RNAi screen for nuclear actin reveals a network of cofilin regulators
Dopie, Joseph, Rajakyla, Eeva K., Joensuu, Merja S., Huet, Guillaume, Ferrantelli, Evelina, Xie, Tiao, Jaalinoja, Harri, Jokitalo, Eija and Vartiainen, Maria K. (2015). Genome-wide RNAi screen for nuclear actin reveals a network of cofilin regulators. Journal of Cell Science, 128 (13), 2388-2400. doi: 10.1242/jcs.169441
ER sheet persistence is coupled to myosin 1c-regulated dynamic actin filament arrays
Joensuu, Merja, Belevich, Ilya, Ramo, Olli, Nevzorov, Ilya, Vihinen, Helena, Puhka, Maija, Witkos, Tomasz M., Lowe, Martin, Vartiainen, Maria K. and Jokitalo, Eija (2014). ER sheet persistence is coupled to myosin 1c-regulated dynamic actin filament arrays. Molecular Biology of the Cell, 25 (7), 1111-1126. doi: 10.1091/mbc.E13-12-0712
Puhka, Maija, Joensuu, Merja, Vihinen, Helena, Belevich, Ilya and Jokitalo, Eija (2012). Progressive sheet-to-tubule transformation is a general mechanism for endoplasmic reticulum partitioning in dividing mammalian cells. Molecular Biology of the Cell, 23 (13), 2424-2432. doi: 10.1091/mbc.E10-12-0950
Puhka, Maija, Vihinen, Helena, Joensuu, Merja and Jokitalo, Eija (2007). Endoplasmic reticulum remains continuous and undergoes sheet-to-tubule transformation during cell division in mammalian cells. Journal of Cell Biology, 179 (5), 895-909. doi: 10.1083/jcb.200705112
Tau - A master regulator of recycling synaptic vesicle clustering at the presynapse
Sanders, Shanley F., Mollazade, Mahdie, Wallis, Tristan P., Gormal, Rachel S., Joensuu, Merja, Wark, Jesse R., Waardenberg, Ashley J., Small, Christopher, Graham, Mark E., Martinez-Marmol, Ramon and Meunier, Frederic A. (2023). Tau - A master regulator of recycling synaptic vesicle clustering at the presynapse. ISN-ESN 2023 Meeting, Porto, Portugal, 8 - 11 August 2023. Chichester, West Sussex, United Kingdom: Wiley-Blackwell Publishing. doi: 10.1111/jnc.15897
Joensuu, Merja, Blum, Ailisa, Mollazade, Mahdie, Lanoue, Vanessa, Padmanabhan, Pranesh, Small, Christopher, Mahrhold, Stefan, Krez, Nadja, Rummel, Andreas and Meunier, Frederic A. (2018). Super-resolving botulinum neurotoxin type A molecules: from surface landing to internalization in synaptic vesicles. TOXINS 2019: Basic Science and Clinical Aspects of Botulinum and Other Neurotoxins, Copenhagen, Denmark, 16-19 January 2019. Kidlington, Oxford, United Kingdom: Pergamon Press. doi: 10.1016/j.toxicon.2018.11.122
Nanoscale imaging of botulinum neurotoxin type a retrograde axonal trafficking
Harper, Callista B., Wang, Tong, Joensuu, Merja, Papadopulos, Andreas and Meunier, Frederic A. (2017). Nanoscale imaging of botulinum neurotoxin type a retrograde axonal trafficking. TOXINS: Basic Science and Clinical Aspects of Botulinum and other Neurotoxins, Madrid, Spain, 18-21 January 2017. Oxford, United Kingdom: Pergamon Press. doi: 10.1016/j.toxicon.2016.11.106
BoNT/A binding and endocytosis in primary neurons
Joensuu, Merja and Meunier, Frederic (2023). BoNT/A binding and endocytosis in primary neurons. The University of Queensland. (Dataset) doi: 10.48610/06039ff
Longield et al_2023_NatComm_Raw
Gormal, Rachel, Meunier, Frederic, Martinez-Marmol, Ramon, Mollazade, Mahdie, Wallis, Tristan, Joensuu, Merja, Sanders, Shanley and Small, Christopher (2023). Longield et al_2023_NatComm_Raw. The University of Queensland. (Dataset) doi: 10.48610/a9c9def
(2020–2023) RL Cooper Medical Research Foundation Limited
Dynamic and molecular determinants of nanoscale organization of different synaptic vesicle pools
(2020) UQ Early Career Researcher
A novel role for saturated fatty acids in learning and memory
(2019–2022) ARC Discovery Early Career Researcher Award
(2018) Ian Potter Foundation
Secretory pathway membrane trafficking and lipid metabolism in health and disease
Doctor Philosophy — Principal Advisor
The role of saturated free fatty acids in learning and memory
Doctor Philosophy — Principal Advisor
(2022) Doctor Philosophy — Associate Advisor
Other advisors:
(2022) Doctor Philosophy — Associate Advisor
Other advisors: