Academic Staff

My research is focused on developing image analysis methods that enable quantification of the plant endoplasmic reticulum (ER) and identification of novel ER shaping proteins. Of particular interest is the Lunapark protein family which play a key role in maintaining proper ER structure and contains the first known cisternae specific marker. I have a strong focus on image analysis and advanced microscopy techniques.

Research updates available at @Charly_Pain

Journal articles

• Kerselidou D, Dohai BS, Nelson DR, Daakour S, De Cock N, Al Oula Hassoun Z, Kim D-K, Olivet J, El Assal DC , Jaiswal A, Alzahmi A, Saha D, Pain C, Matthijssens F, Lemaitre P, Herfs M, Chapuis J, Ghesquiere B, Vertommen D, Kriechbaumer V, Knoops K, Lopez-Iglesias C, van Zandvoort M, Lambert J-C, Hanson J, Desmet C ,Thiry M, Lauersen K, Vidal M, Van Vlierberghe P, Dequiedt F, Salehi-Ashtiani K, Twizere J-C, 'Alternative glycosylation controls endoplasmic reticulum dynamics and tubular extension in mammalian cells'
  Science Advances 7 (19) (2021)
  ISSN: 2375-2548 eISSN: 2375-2548
  Abstract

  The endoplasmic reticulum (ER) is a central eukaryotic organelle with a tubular network made of hairpin proteins linked by hydrolysis of GTP nucleotides. Among post-translational modifications initiated at the ER level, glycosylation is the most common reaction. However, our understanding of the impact of glycosylation on the ER structure remains unclear. Here, we show that Exostosin-1 (EXT1) glycosyltransferase, an enzyme involved in N-glycosylation, is a key regulator of the ER morphology and dynamics. We have integrated multi-omics data and super-resolution imaging to characterize the broad effect of EXT1 inactivation, including the ER shape-dynamics-function relationships in mammalian cells. We have observed that inactivating EXT1 induces cell enlargement and enhances metabolic switches such as protein secretion. In particular, suppressing EXT1 in mouse thymocytes causes developmental dysfunctions associated with the ER network extension. Finally, our data illuminate the physical and functional aspects of the ER proteome-glycome-lipidome-structure axis, with implications in biotechnology and medicine. 
  

  Website 
• Zang J, Klemm S, Pain C, Duckney P, Bao Z, Stamm G, Kriechbaumer V, Bürstenbinder K, Hussey PJ, Wang P, 'A novel plant actin-microtubule bridging complex regulates cytoskeletal and ER structure at Endoplasmic Reticulum-Plasma Membrane Contact Sites (EPCS) '
  Current Biology 31 (6) (2021) pp.1251-1260
  ISSN: 0960-9822
  Abstract

  In plants, the cortical ER network is connected to the plasma membrane through the ER-PM contact sites (EPCS), whose structures are maintained by EPCS resident proteins and the cytoskeleton [1-7] . Strong co-alignment between EPCS and the cytoskeleton is observed in plants [1, 8], but little is known of how the cytoskeleton is maintained and regulated at the EPCS. Here we have used a yeast-two-hybrid screen and subsequent in vivo interaction studies in plants by FRET-FLIM analysis, to identify two microtubule binding proteins, KLCR1 (Kinesin Light Chain Related protein 1) and IQD2 (IQ67-Domain 2) that interact with the actin binding protein NET3C and form a component of plant EPCS, that mediates the link between the actin and microtubule networks. The NET3C-KLCR1-IQD2 module, acting as an actin-microtubule bridging complex, has a direct influence on ER morphology and EPCS structure. Their loss of function mutants, net3a/NET3C RNAi, klcr1 or iqd2, exhibit defects in pavement cell morphology which we suggest is linked to the disorganization of both actin filaments and microtubules. In conclusion, our results reveal a novel cytoskeletal associated complex, which is essential for the maintenance and organization of cytoskeletal structure and ER morphology at the EPCS, and for normal plant cell morphogenesis.
  

  Website 
• Pain C, Kriechbaumer V, 'Defining the dance: quantification and classification of ER dynamics'
  Journal of Experimental Botany 71 (6) (2019) pp.1757-1762
  ISSN: 0022-0957 eISSN: 1460-2431
  Abstract

  The availability of quantification methods for sub-cellular organelle dynamic analysis has increased rapidly over the last 20 years. The application of these techniques to contiguous sub-cellular structures that exhibit dynamic re-modelling over a range of scales and orientations is challenging as quantification of ‘movement’ rarely corresponds to traditional, qualitative classifications of types of organelle movement. The plant endoplasmic reticulum represents a particular challenge for dynamic quantification as it itself is an entirely contiguous organelle that is in a constant state of flux and gross remodelling, controlled by the actinomyosin cytoskeleton.
  

  Website 

Pain, C. Kriechbaumer, V. Kittelmann, M. Hawes, C. & Fricker, M. (2019). Quantitative analysis of plant ER architecture and dynamics. Nature Communications, 10(1), 984.

Kriechbaumer, V. Breeze, E. Pain, C. Tolmie, F. Frigerio, L. & Hawes, C. (2018). Arabidopsis Lunapark proteins are involved in ER cisternae formation. New Phytologist, 219(3), 990–1004.