Possible Rotation Projects:
- Define the molecular architecture of transition zone and collarette structures involved in intraflagellar transport initiation using cryo-electron tomography.
- Investigate how ciliopathy-associated proteins such as RP2, ARL3, or ARL13 regulate IFT organization and flagellum assembly.
Develop and apply correlative imaging and image-analysis approaches to map ciliary-base proteins in relation to native ultrastructure.
Training Technologies Used:
- Cryo-electron tomography
- Cryo-focused ion beam milling
- Transmission electron microscopy
- Subtomogram averaging
- Correlative light and electron microscopy
- Fluorescence microscopy
- Expansion microscopy
- Molecular genetics/RNAi
- Immunofluorescence
- Protein tagging
- 3D segmentation
- AI-based computational image analysis.
- B.S. Life Sciences, 2004-2008, Wuhan University, Wuhan, China
- Ph.D., in Biological Sciences 2008-2014, National University of Singapore, Singapore
- Research Scientist 2017-2021, Stanford University, Stanford, California, United States
- Postdoc Associate 2016-2017, Baylor College of Medicine, Houston, Texas, United States
- Research Fellow 2014-2016, Mechanobiology Institute, Singapore
Staggers SR, Zhao M, Harrigan O, Absalon S, Huang Y, Cheng Z, Zhao Y, Chen M, Sun SY *. In situ cryo-ET reveals restricted docking of intraflagellar transport at the base of the trypanosome flagellum. bioRxiv. 2025:2025.12.23.690766. doi: 10.64898/2025.12.23.690766.
Blauwkamp JA, Rajaram K, Staggers SR, Harrigan O, Doud EH, Xu W, Ke H, Prigge ST, Sun SY, Absalon S *. An essential adaptor for apicoplast fission and inheritance in malaria parasites. Nat Commun. 2025;16(1):11325. Epub 20251127. doi: 10.1038/s41467-025-66393-5. PubMed PMID: 41309594; PMCID: PMC12722261.
Huang Y, Dong X, Sun SY, Lim TK, Lin Q, He CY *. ARL3 GTPases facilitate ODA16 unloading from IFT in motile cilia. Sci Adv. 2024 Sep 6;10(36):eadq2950. PubMed Central PMCID: PMC11373600.
Sun SY *, Segev-Zarko L-a *, Pintilie GD, Kim CY, Staggers SR, Schmid MF, Egan ES, Chiu W, Boothroyd JC. Cryogenic electron tomography reveals novel structures in the apical complex of Plasmodium falciparum. mBio. 2024 Apr 10;15(4):e0286423. PubMed Central PMCID: PMC11005440.
Segev-Zarko L-A, Dahlberg PD, Sun SY, Pelt DM, Sethian JA, Chiu W*, Boothroyd JC*. n.d. Ionophore-stimulation promotes re-organization of the invasion machinery of Toxoplasma gondii. PNAS Nexus. 2022 Sep:pgac183. doi: 10.1093/pnasnexus/pgac183. PMID: 36329726; PMCID: PMC9615128.
Sun SY, Segev-Zarko LA, Chen M, Pintilie GD, Schmid MF, Ludtke SJ, Boothroyd JC *, Chiu W *. Cryo-ET of Toxoplasma parasites gives subnanometer insight into tubulin-based structures. Proc Natl Acad Sci U S A. 2022 Feb 8;119(6) PubMed Central PMCID: PMC8832990.
Tierney W, Vicino I, Sun S, Chiu W, Engel E, Taylor M, Hogue I *. Methods and Applications of Campenot Trichamber Neuronal Cultures for the Study of Neuroinvasive Viruses [Internet]. 2021. Available from: http://dx.doi.org/10.20944/preprints202105.0098.v1
Chen M, Bell JM, Shi X, Sun SY, Wang Z, Ludtke SJ *. A complete data processing workflow for cryo-ET and subtomogram averaging. Nat Methods. 2019 Nov;16(11):1161–1168. PMCID: PMC6858567
Sun SY, Kaelber JT, Chen M, Dong X, Nematbakhsh Y, Shi J, Dougherty M, Lim CT, Schmid MF, Chiu W *, He CY *. Flagellum couples cell shape to motility in. Proc Natl Acad Sci U S A. 2018 Jun 26;115(26):E5916–E5925. PMCID: PMC6042131
https://www.biorxiv.org/content/10.64898/2025.12.23.690766v1?utm_source=chatgpt.com
https://pubmed.ncbi.nlm.nih.gov/41309594/
https://pubmed.ncbi.nlm.nih.gov/39231220/
https://pubmed.ncbi.nlm.nih.gov/38456679/
https://pubmed.ncbi.nlm.nih.gov/36329726/
https://pubmed.ncbi.nlm.nih.gov/35121661/
https://pubmed.ncbi.nlm.nih.gov/35412277/
The Sun laboratory uses cellular cryo-electron tomography, cryo-focused ion beam milling, and correlative imaging approaches to investigate the molecular architecture and mechanisms of cilia and flagella. Our research focuses on how the transition zone, transition fibers, and associated ciliary-base structures regulate intraflagellar transport, ciliary gating, and organelle assembly in the protozoan parasite Trypanosoma brucei. By visualizing these processes directly in their native cellular context, we aim to define how conserved ciliary structures control protein trafficking and flagellum biogenesis.
A major goal of the lab is to understand how defects in ciliary-base organization disrupt intraflagellar transport and contribute to human parasite pathogenesis or human ciliopathies. We combine in situ structural biology with knockdown, fluorescence microscopy, expansion microscopy, and image analysis to connect molecular architecture with cellular function. In addition to T. brucei, the lab is expanding comparative studies to other ciliated systems to identify conserved principles of ciliary gating and transport regulation.
