The autophagic membrane tether ATG2A transfers lipids between membranes
Posted on: 12 April 2019 , updated on: 24 April 2019
Preprint posted on 20 February 2019
Article now published in eLife at http://dx.doi.org/10.7554/eLife.45777
Fattening up for autophagy: lipid transfer by ATG2A could enable expansion of the phagophore
Selected by Sandra Malmgren Hill
Categories: biochemistry, biophysics, cell biology, molecular biology, synthetic biology
Context
Autophagy is an essential process for degradation and recycling of material where cytosolic material, including whole organelles, are enclosed in a double-membraned vesicle and fused to the lysosome for proteolytic digestion. The location of autophagosome formation is determined by a local enrichment of the lipid signaling molecule phosphatidyinositol-3-phosphate (PI(3)P) (Bento et al., 2016). This lipid signal recruits PI(3)P-binding proteins to the site, and a cascade of protein recruitment allows for membrane curvature, and formation of a cup-shaped membrane precursor called the phagophore. The phagophore expands and encloses its cargo to form the mature autophagosome, and the autophagosome fuses with the lysosome for the proteolytic degradation of autophagosome content. While a lot is known about the molecular mechanisms inducing autophagy, and the key effectors mediating autophagosome formation, the exact location of autophagosome formation and the source of phagophore membrane material is debated (Tooze and Yoshimori, 2010). The ER, mitochondrial contact sites and the recycling endosome have been suggested to act as sites for phagophore formation and the phagophore has been suggested to grow due to de novo lipid synthesis, and/or donation from various membrane sources such as the ER, endosomes and lipid droplets (Carlsson and Simonsen, 2015).
In this preprint, the authors look into the process of phagophore expansion, and show that the protein ATG2A, which is recruited to the phagophore together with the PI(3)P-binding WIPI proteins (Kotani et al., 2018), acts as a lipid transferring protein. The authors suggest that this function could allow it to transfer lipids from the ER to the growing phagophore and thereby mediate phagophore expansion.
Major findings
Atg2 is a protein consisting of two membrane-binding domains: the N-terminal corein domain and the C-terminal CAD domain (Chowdhury et al., 2018). Yeast Atg2 has been shown to bind and tether liposomes, and it is suggested that, at least in yeast, Atg2 could tether the phagophore to the ER to allow membrane extension (Kotani et al., 2018). In this preprint by Maeda et al, the authors utilize in vitro applications to show that the mammalian homologue ATG2A not only tethers liposomal membranes (Chowdhury et al., 2018), but also transfers lipids between them.
The authors use small and large unilamellar vesicles (SUVs and LUVs respectively) to represent high versus low curvature membranes, and show that ATG2A can extract lipids efficiently from LUVs and dissociate from the membrane with those lipids. The reverse action of lipid transfer can also be observed, where ATG2A bound to a lipid can unload this lipid and insert it into the membrane of LUVs. Using an energy-transfer based assay to study the kinetics of lipid transport, the authors show that ATG2A facilitates lipid transfer also between high curvature SUVs.
Previous data showed that ATG2A tethering of the lower curvature membrane LUVs could only be achieved upon binding of ATG2A and WIPI4 and required PI(3)P present on at least one of the two vesicles to be tethered. Data in this preprint confirm the necessity of WIPI-linked tethering for lipid transfer, and show that ATG2A can mediate lipid transfer between a PI(3)P-containing membrane and a PI(3)P-free membrane when WIPI4 or WIPI1 is added. The authors also show that the lipid transfer is bidirectional: When PI(3)P is incorporated in the acceptor membrane instead of the donor membrane, causing a shift in the orientation of ATG2A with the C-terminal CAD tip towards the PI(3)P bound WIPI protein, lipid transfer is observed at the same rate as when the ATG2A has its C-terminal bound to PI(3)P-WIPI on the donor membrane.
A direct interaction between ATG2A and WIPI1 could not be observed, instead the authors present data illustrating that ATG2A and WIPI proteins cooperatively associate with PI(3)P containing membranes.
Based on this data, the authors present a bridge mechanism for how ATG2A transfer lipids between membranes (Figure 1). In phagophore extension, hypothesizing that the phagophore is formed from PI(3)P-positive structures on the ER, ATG2A forms a bridge together with WIPI1 or WIPI4 to provide lipid transfer from the ER to the highly curved ends of the expanding phagophore (Fig. 1A). The bridge mechanism also holds true for ATG2A lipid transfer between other high curvature membranes (Fig 1B), where ATG2A can be bound in either orientation. For lipid transfer between low curvature membranes, the presence of PI(3)P and WIPI proteins will guide the direction of ATG2A (Fig 1C), although it is currently unknown if and how this affects the direction of lipid transfer.
Figure 1: A bridge model explains the mode of ATG2A-mediated lipid transfer. A) Lipid transfer by ATG2A from ER to the phagophore could represent a mechanism for phagophore expansion. ATG2A can also transfer lipids between high curvature membranes (SUVs) independently of WIPI proteins (B), but requires the presence of these proteins for lipid transfer between high curvature membranes (LUVs) (C). Figure from the preprint by Maeda et al., made available under a CC-BY-NC-ND 4.0 international license.
Why I choose this preprint
I think the question of where and how autophagosomes are formed is very interesting, and it is a field of study that is rapidly evolving with a lot of new data and theories being published continuously. The preprint highlighted in this preLight utilizes clever in vitro experiments to test their hypothesis on lipid transfer for membrane expansion, and I look forward to following the progress on how these findings can be correlated with in vivo observations.
Open Questions
- This preprint provides convincing evidence for lipid transfer activity of ATG2A in vitro, but the in vivo physiological role of this mechanism remains to be investigated. What are the lipids transferred by ATG2A, and what are the donor membranes? The authors present a model where phagophore expansion is mediated by transfer of lipids from the ER, but is it possible that ATG2A could also mediate lipid transfer from other membrane sources, such as Atg9-vesicles which Atg2 have been reported to interact with (Gomez-Sanchez et al., 2018)?
- The autophagy deficient Atg210-12D mutant retains its interaction with WIPI homologue Atg18, and localizes to the site of phagophore formation but cannot mediate expansion (Kotani et al., 2018). Could the deleted region be important for the lipid transferring activity of Atg2?
- What shifts the equilibrium to favor transfer in a certain direction? The authors’ model of phagophore expansion requires a unidirectional transport of lipids, yet the in vitro data shows that lipid transport is bidirectional, regardless of the orientation of ATG2A. Thus, there must be additional regulatory factors involved to affect the binding affinity of ATG2A N-term versus C-term and regulate the lipid transfer efficiency.
- Do the WIPI proteins (WIPI1 vs WIPI4) have different roles in ATG2A mediated lipid transfer or are their functions redundant? The authors present data on WIPI1 self-oligomerisation affecting vesicle clustering, which could indicate a role in regulation of membrane curvature. If WIPIs have different properties of self-oligomerisation, is it possible that WIPIs affect different lipid transfers to regulate curvature and shape the autophagosome?
References
Bento, C.F., Renna, M., Ghislat, G., Puri, C., Ashkenazi, A., Vicinanza, M., Menzies, F.M., and Rubinsztein, D.C. (2016). Mammalian Autophagy: How Does It Work? Annu Rev Biochem 85, 685-713.
Carlsson, S.R., and Simonsen, A. (2015). Membrane dynamics in autophagosome biogenesis. J Cell Sci 128, 193-205.
Chowdhury, S., Otomo, C., Leitner, A., Ohashi, K., Aebersold, R., Lander, G.C., and Otomo, T. (2018). Insights into autophagosome biogenesis from structural and biochemical analyses of the ATG2A-WIPI4 complex. Proc Natl Acad Sci U S A 115, E9792-E9801.
Gomez-Sanchez, R., Rose, J., Guimaraes, R., Mari, M., Papinski, D., Rieter, E., Geerts, W.J., Hardenberg, R., Kraft, C., Ungermann, C., et al. (2018). Atg9 establishes Atg2-dependent contact sites between the endoplasmic reticulum and phagophores. The Journal of cell biology 217, 2743-2763.
Kotani, T., Kirisako, H., Koizumi, M., Ohsumi, Y., and Nakatogawa, H. (2018). The Atg2-Atg18 complex tethers pre-autophagosomal membranes to the endoplasmic reticulum for autophagosome formation. Proc Natl Acad Sci U S A 115, 10363-10368.
Tooze, S.A., and Yoshimori, T. (2010). The origin of the autophagosomal membrane. Nature cell biology 12, 831-835.
doi: https://doi.org/10.1242/prelights.10160
Read preprint
(No Ratings Yet)Sign up to customise the site to your preferences and to receive alerts
Register hereAlso in the biochemistry category:
Triglyceride metabolism controls inflammation and APOE4-associated disease states in microglia
Gustavo Stelzer, Marcus Oliveira
Impaired 26S proteasome causes learning and memory deficiency and induces neuroinflammation mediated by NF-κB in mice
Gustavo Stelzer, Marcus Oliveira
Notch3 is a genetic modifier of NODAL signalling for patterning asymmetry during mouse heart looping
Bhaval Parmar
Also in the biophysics category:
Restoring mechanophenotype reverts malignant properties of ECM-enriched vocal fold cancer
Teodora Piskova
Motor Clustering Enhances Kinesin-driven Vesicle Transport
Sharvari Pitke
Global coordination of protrusive forces in migrating immune cells
yohalie kalukula
Also in the cell biology category:
Restoring mechanophenotype reverts malignant properties of ECM-enriched vocal fold cancer
Teodora Piskova
Germplasm stability in zebrafish requires maternal Tdrd6a and Tdrd6c
Justin Gutkowski
Leukocytes use endothelial membrane tunnels to extravasate the vasculature
Felipe Del Valle Batalla
Also in the molecular biology category:
Germplasm stability in zebrafish requires maternal Tdrd6a and Tdrd6c
Justin Gutkowski
Platelet-derived LPA16:0 inhibits adult neurogenesis and stress resilience in anxiety disorder
Harvey Roweth
Green synthesized silver nanoparticles from Moringa: Potential for preventative treatment of SARS-CoV-2 contaminated water
Safieh Shah, Benjamin Dominik Maier
Also in the synthetic biology category:
Enhancer cooperativity can compensate for loss of activity over large genomic distances
Milan Antonovic
Discovery and Validation of Context-Dependent Synthetic Mammalian Promoters
Jessica L. Teo
Genetically encoded multimeric tags for intracellular protein localisation in cryo-EM
Martyna Kosno-Vega
preLists in the biochemistry category:
BSCB-Biochemical Society 2024 Cell Migration meeting
This preList features preprints that were discussed and presented during the BSCB-Biochemical Society 2024 Cell Migration meeting in Birmingham, UK in April 2024. Kindly put together by Sara Morais da Silva, Reviews Editor at Journal of Cell Science.
| List by | Reinier Prosee |
Peer Review in Biomedical Sciences
Communication of scientific knowledge has changed dramatically in recent decades and the public perception of scientific discoveries depends on the peer review process of articles published in scientific journals. Preprints are key vehicles for the dissemination of scientific discoveries, but they are still not properly recognized by the scientific community since peer review is very limited. On the other hand, peer review is very heterogeneous and a fundamental aspect to improve it is to train young scientists on how to think critically and how to evaluate scientific knowledge in a professional way. Thus, this course aims to: i) train students on how to perform peer review of scientific manuscripts in a professional manner; ii) develop students' critical thinking; iii) contribute to the appreciation of preprints as important vehicles for the dissemination of scientific knowledge without restrictions; iv) contribute to the development of students' curricula, as their opinions will be published and indexed on the preLights platform. The evaluations will be based on qualitative analyses of the oral presentations of preprints in the field of biomedical sciences deposited in the bioRxiv server, of the critical reports written by the students, as well as of the participation of the students during the preprints discussions.
| List by | Marcus Oliveira et al. |
CellBio 2022 – An ASCB/EMBO Meeting
This preLists features preprints that were discussed and presented during the CellBio 2022 meeting in Washington, DC in December 2022.
| List by | Nadja Hümpfer et al. |
20th “Genetics Workshops in Hungary”, Szeged (25th, September)
In this annual conference, Hungarian geneticists, biochemists and biotechnologists presented their works. Link: http://group.szbk.u-szeged.hu/minikonf/archive/prg2021.pdf
| List by | Nándor Lipták |
Fibroblasts
The advances in fibroblast biology preList explores the recent discoveries and preprints of the fibroblast world. Get ready to immerse yourself with this list created for fibroblasts aficionados and lovers, and beyond. Here, my goal is to include preprints of fibroblast biology, heterogeneity, fate, extracellular matrix, behavior, topography, single-cell atlases, spatial transcriptomics, and their matrix!
| List by | Osvaldo Contreras |
ASCB EMBO Annual Meeting 2019
A collection of preprints presented at the 2019 ASCB EMBO Meeting in Washington, DC (December 7-11)
| List by | Madhuja Samaddar et al. |
EMBL Seeing is Believing – Imaging the Molecular Processes of Life
Preprints discussed at the 2019 edition of Seeing is Believing, at EMBL Heidelberg from the 9th-12th October 2019
| List by | Dey Lab |
Cellular metabolism
A curated list of preprints related to cellular metabolism at Biorxiv by Pablo Ranea Robles from the Prelights community. Special interest on lipid metabolism, peroxisomes and mitochondria.
| List by | Pablo Ranea Robles |
MitoList
This list of preprints is focused on work expanding our knowledge on mitochondria in any organism, tissue or cell type, from the normal biology to the pathology.
| List by | Sandra Franco Iborra |
Also in the biophysics category:
preLights peer support – preprints of interest
This is a preprint repository to organise the preprints and preLights covered through the 'preLights peer support' initiative.
| List by | preLights peer support |
66th Biophysical Society Annual Meeting, 2022
Preprints presented at the 66th BPS Annual Meeting, Feb 19 - 23, 2022 (The below list is not exhaustive and the preprints are listed in no particular order.)
| List by | Soni Mohapatra |
EMBL Synthetic Morphogenesis: From Gene Circuits to Tissue Architecture (2021)
A list of preprints mentioned at the #EESmorphoG virtual meeting in 2021.
| List by | Alex Eve |
Biophysical Society Meeting 2020
Some preprints presented at the Biophysical Society Meeting 2020 in San Diego, USA.
| List by | Tessa Sinnige |
ASCB EMBO Annual Meeting 2019
A collection of preprints presented at the 2019 ASCB EMBO Meeting in Washington, DC (December 7-11)
| List by | Madhuja Samaddar et al. |
EMBL Seeing is Believing – Imaging the Molecular Processes of Life
Preprints discussed at the 2019 edition of Seeing is Believing, at EMBL Heidelberg from the 9th-12th October 2019
| List by | Dey Lab |
Biomolecular NMR
Preprints related to the application and development of biomolecular NMR spectroscopy
| List by | Reid Alderson |
Biophysical Society Annual Meeting 2019
Few of the preprints that were discussed in the recent BPS annual meeting at Baltimore, USA
| List by | Joseph Jose Thottacherry |
Also in the cell biology category:
November in preprints – the CellBio edition
This is the first community-driven preList! A group of preLighters, with expertise in different areas of cell biology, have worked together to create this preprint reading lists for researchers with an interest in cell biology. Categories include: 1) cancer cell biology 2) cell cycle and division 3) cell migration and cytoskeleton 4) cell organelles and organisation 5) cell signalling and mechanosensing 6) genetics/gene expression
| List by | Felipe Del Valle Batalla et al. |
BSCB-Biochemical Society 2024 Cell Migration meeting
This preList features preprints that were discussed and presented during the BSCB-Biochemical Society 2024 Cell Migration meeting in Birmingham, UK in April 2024. Kindly put together by Sara Morais da Silva, Reviews Editor at Journal of Cell Science.
| List by | Reinier Prosee |
‘In preprints’ from Development 2022-2023
A list of the preprints featured in Development's 'In preprints' articles between 2022-2023
| List by | Alex Eve, Katherine Brown |
preLights peer support – preprints of interest
This is a preprint repository to organise the preprints and preLights covered through the 'preLights peer support' initiative.
| List by | preLights peer support |
The Society for Developmental Biology 82nd Annual Meeting
This preList is made up of the preprints discussed during the Society for Developmental Biology 82nd Annual Meeting that took place in Chicago in July 2023.
| List by | Joyce Yu, Katherine Brown |
CSHL 87th Symposium: Stem Cells
Preprints mentioned by speakers at the #CSHLsymp23
| List by | Alex Eve |
Journal of Cell Science meeting ‘Imaging Cell Dynamics’
This preList highlights the preprints discussed at the JCS meeting 'Imaging Cell Dynamics'. The meeting was held from 14 - 17 May 2023 in Lisbon, Portugal and was organised by Erika Holzbaur, Jennifer Lippincott-Schwartz, Rob Parton and Michael Way.
| List by | Helen Zenner |
9th International Symposium on the Biology of Vertebrate Sex Determination
This preList contains preprints discussed during the 9th International Symposium on the Biology of Vertebrate Sex Determination. This conference was held in Kona, Hawaii from April 17th to 21st 2023.
| List by | Martin Estermann |
Alumni picks – preLights 5th Birthday
This preList contains preprints that were picked and highlighted by preLights Alumni - an initiative that was set up to mark preLights 5th birthday. More entries will follow throughout February and March 2023.
| List by | Sergio Menchero et al. |
CellBio 2022 – An ASCB/EMBO Meeting
This preLists features preprints that were discussed and presented during the CellBio 2022 meeting in Washington, DC in December 2022.
| List by | Nadja Hümpfer et al. |
Fibroblasts
The advances in fibroblast biology preList explores the recent discoveries and preprints of the fibroblast world. Get ready to immerse yourself with this list created for fibroblasts aficionados and lovers, and beyond. Here, my goal is to include preprints of fibroblast biology, heterogeneity, fate, extracellular matrix, behavior, topography, single-cell atlases, spatial transcriptomics, and their matrix!
| List by | Osvaldo Contreras |
EMBL Synthetic Morphogenesis: From Gene Circuits to Tissue Architecture (2021)
A list of preprints mentioned at the #EESmorphoG virtual meeting in 2021.
| List by | Alex Eve |
FENS 2020
A collection of preprints presented during the virtual meeting of the Federation of European Neuroscience Societies (FENS) in 2020
| List by | Ana Dorrego-Rivas |
Planar Cell Polarity – PCP
This preList contains preprints about the latest findings on Planar Cell Polarity (PCP) in various model organisms at the molecular, cellular and tissue levels.
| List by | Ana Dorrego-Rivas |
BioMalPar XVI: Biology and Pathology of the Malaria Parasite
[under construction] Preprints presented at the (fully virtual) EMBL BioMalPar XVI, 17-18 May 2020 #emblmalaria
| List by | Dey Lab, Samantha Seah |
1
Cell Polarity
Recent research from the field of cell polarity is summarized in this list of preprints. It comprises of studies focusing on various forms of cell polarity ranging from epithelial polarity, planar cell polarity to front-to-rear polarity.
| List by | Yamini Ravichandran |
TAGC 2020
Preprints recently presented at the virtual Allied Genetics Conference, April 22-26, 2020. #TAGC20
| List by | Maiko Kitaoka et al. |
3D Gastruloids
A curated list of preprints related to Gastruloids (in vitro models of early development obtained by 3D aggregation of embryonic cells). Updated until July 2021.
| List by | Paul Gerald L. Sanchez and Stefano Vianello |
ECFG15 – Fungal biology
Preprints presented at 15th European Conference on Fungal Genetics 17-20 February 2020 Rome
| List by | Hiral Shah |
ASCB EMBO Annual Meeting 2019
A collection of preprints presented at the 2019 ASCB EMBO Meeting in Washington, DC (December 7-11)
| List by | Madhuja Samaddar et al. |
EMBL Seeing is Believing – Imaging the Molecular Processes of Life
Preprints discussed at the 2019 edition of Seeing is Believing, at EMBL Heidelberg from the 9th-12th October 2019
| List by | Dey Lab |
Autophagy
Preprints on autophagy and lysosomal degradation and its role in neurodegeneration and disease. Includes molecular mechanisms, upstream signalling and regulation as well as studies on pharmaceutical interventions to upregulate the process.
| List by | Sandra Malmgren Hill |
Lung Disease and Regeneration
This preprint list compiles highlights from the field of lung biology.
| List by | Rob Hynds |
Cellular metabolism
A curated list of preprints related to cellular metabolism at Biorxiv by Pablo Ranea Robles from the Prelights community. Special interest on lipid metabolism, peroxisomes and mitochondria.
| List by | Pablo Ranea Robles |
BSCB/BSDB Annual Meeting 2019
Preprints presented at the BSCB/BSDB Annual Meeting 2019
| List by | Dey Lab |
MitoList
This list of preprints is focused on work expanding our knowledge on mitochondria in any organism, tissue or cell type, from the normal biology to the pathology.
| List by | Sandra Franco Iborra |
ASCB/EMBO Annual Meeting 2018
This list relates to preprints that were discussed at the recent ASCB conference.
| List by | Dey Lab, Amanda Haage |
Also in the molecular biology category:
2024 Hypothalamus GRC
This 2024 Hypothalamus GRC (Gordon Research Conference) preList offers an overview of cutting-edge research focused on the hypothalamus, a critical brain region involved in regulating homeostasis, behavior, and neuroendocrine functions. The studies included cover a range of topics, including neural circuits, molecular mechanisms, and the role of the hypothalamus in health and disease. This collection highlights some of the latest advances in understanding hypothalamic function, with potential implications for treating disorders such as obesity, stress, and metabolic diseases.
| List by | Nathalie Krauth |
BSCB-Biochemical Society 2024 Cell Migration meeting
This preList features preprints that were discussed and presented during the BSCB-Biochemical Society 2024 Cell Migration meeting in Birmingham, UK in April 2024. Kindly put together by Sara Morais da Silva, Reviews Editor at Journal of Cell Science.
| List by | Reinier Prosee |
‘In preprints’ from Development 2022-2023
A list of the preprints featured in Development's 'In preprints' articles between 2022-2023
| List by | Alex Eve, Katherine Brown |
CSHL 87th Symposium: Stem Cells
Preprints mentioned by speakers at the #CSHLsymp23
| List by | Alex Eve |
9th International Symposium on the Biology of Vertebrate Sex Determination
This preList contains preprints discussed during the 9th International Symposium on the Biology of Vertebrate Sex Determination. This conference was held in Kona, Hawaii from April 17th to 21st 2023.
| List by | Martin Estermann |
Alumni picks – preLights 5th Birthday
This preList contains preprints that were picked and highlighted by preLights Alumni - an initiative that was set up to mark preLights 5th birthday. More entries will follow throughout February and March 2023.
| List by | Sergio Menchero et al. |
CellBio 2022 – An ASCB/EMBO Meeting
This preLists features preprints that were discussed and presented during the CellBio 2022 meeting in Washington, DC in December 2022.
| List by | Nadja Hümpfer et al. |
EMBL Synthetic Morphogenesis: From Gene Circuits to Tissue Architecture (2021)
A list of preprints mentioned at the #EESmorphoG virtual meeting in 2021.
| List by | Alex Eve |
FENS 2020
A collection of preprints presented during the virtual meeting of the Federation of European Neuroscience Societies (FENS) in 2020
| List by | Ana Dorrego-Rivas |
ECFG15 – Fungal biology
Preprints presented at 15th European Conference on Fungal Genetics 17-20 February 2020 Rome
| List by | Hiral Shah |
ASCB EMBO Annual Meeting 2019
A collection of preprints presented at the 2019 ASCB EMBO Meeting in Washington, DC (December 7-11)
| List by | Madhuja Samaddar et al. |
Lung Disease and Regeneration
This preprint list compiles highlights from the field of lung biology.
| List by | Rob Hynds |
MitoList
This list of preprints is focused on work expanding our knowledge on mitochondria in any organism, tissue or cell type, from the normal biology to the pathology.
| List by | Sandra Franco Iborra |
Also in the synthetic biology category:
‘In preprints’ from Development 2022-2023
A list of the preprints featured in Development's 'In preprints' articles between 2022-2023
| List by | Alex Eve, Katherine Brown |
EMBL Synthetic Morphogenesis: From Gene Circuits to Tissue Architecture (2021)
A list of preprints mentioned at the #EESmorphoG virtual meeting in 2021.
| List by | Alex Eve |
EMBL Conference: From functional genomics to systems biology
Preprints presented at the virtual EMBL conference "from functional genomics and systems biology", 16-19 November 2020
| List by | Jesus Victorino |
Antimicrobials: Discovery, clinical use, and development of resistance
Preprints that describe the discovery of new antimicrobials and any improvements made regarding their clinical use. Includes preprints that detail the factors affecting antimicrobial selection and the development of antimicrobial resistance.
| List by | Zhang-He Goh |
Advances in Drug Delivery
Advances in formulation technology or targeted delivery methods that describe or develop the distribution of small molecules or large macromolecules to specific parts of the body.
| List by | Zhang-He Goh |