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Sebastian D. Fugmann

Sebastian D. Fugmann




Ph.D., University of Ulm, Germany



Office Tel

+886-3-211-8800 ext.3478




Laboratory of Molecular Immunology


Molecular Immunology, DNA recombination and repair

Lab & Research Interest

All multicellular organisms are constantly challenged by a plethora of potentially lethal pathogens and thus require protection to survive. These defense mechanisms can be broadly divided into the "innate" and the "adaptive" immune systems. The former relies on the recognition of conserved pathogen associated molecular patterns where as the latter utilizes randomly generated antigen receptors, immunoglobulins (Igs) and T cell receptors (TCRs), without pre-defined specificities. The central theme of my laboratory is to understand the molecular mechanisms of programmed gene rearrangements and mutagenesis that generate the diverse antigen receptor repertoires essential for adaptive immunity.

Until now five such gene diversification processes have been reported: V(D)J recombination, class switch recombination (CSR), somatic hypermutation (SHM), immunoglobulin gene conversions (GCV), and the recently discovered assembly of the variable lymphocyte receptors in the jawless vertebrates, lamprey and hagfish. While V(D)J recombination occurs in the Ig and TCR loci of B and T lymphocyte progenitors, CSR, SHM, and GCV are initiated after the encounter of antigen and are restricted to the Ig genes of B lymphocytes. All five processes are unique as they involve the violation of a central dogma, the life-long maintenance of genomic DNA, to efficiently combat potentially deleterious pathogens that are encountered on a daily basis.

Our current work is focused on two specific questions:

1) The evolution of V(D)J recombination and adaptive immunity.

We recently identified a gene pair in the genome of the purple sea urchin (Strongylocentrotus purpuratus) with striking similarity to the vertebrate recombination activating genes 1 and 2 (RAG1 and RAG2 genes. The genes were previously thought to be unique to jawed vertebrates as the sole function of RAG1 and RAG2 is to mediate V(D)J recombination which does not occur in invertebrates. We are currently pursuing in vitro and in vivo studies to characterize their molecular function, their role in sea urchin development and immunity, and the relationship to the classical vertebrate RAG1/2 proteins. We are also studying the sea urchin immune system in general, as it likely represents a transition between the classic invertebrate innate immunity defined in flies and the more advanced immune system of jawed vertebrates.

2) The targeting of SHM and GCV to Ig gene loci.

SHM and GCV are mutagenic processes that are recruited specifically to Ig genes where they exert their beneficial function increasing the affinity of the encoded antibody. As they could be potentially very dangerous when acting on non-Ig genes, there are mechanisms in place to ensure their tight targeting to the correct chromosomal region. We recently discovered mutation enhancer elements (MEEs), a novel class of cis-regulatory elements regulating local genomic stability, as mediators of this targeting. We are currently characterizing these elements to understand their mode of action. We are also trying to identify such elements in mammalian Ig gene loci.



Li, Y. R., Lai, H. W., Huang, H. H., Chen, H. C., Fugmann, S. D., Yang, S. Y.
Trajectory Mapping of the Early Drosophila Germline Reveals Controls of Zygotic Activation and Sex Differentiation.
Genome Research, 2021 Apr:gr.271148.120.


AID/APOBEC-like cytidine deaminases are ancient innate immune mediators in invertebrates.
Liu MC, Liao WY, Buckley KM, Yang SY, Rast JP, Fugmann SD.
Nat Commun. 2018 May 16;9(1):1948. doi: 10.1038/s41467-018-04273-x.

Lectins identify distinct populations of coelomocytes in Strongylocentrotus purpuratus.
Liao WY, Fugmann SD.
PLoS One. 2017 Nov 10;12(11):e0187987. doi: 10.1371/journal.pone.0187987.

Evidence for parallel evolution of a gene involved in the regulation of spermatogenesis.
Wang XR, Ling LB, Huang HH, Lin JJ, Fugmann SD, Yang SY.
Proc Biol Sci. 2017 May 31;284(1855):20170324. doi: 10.1098/rspb.2017.0324.

Collaboration of RAG2 with RAG1-like proteins during the evolution of V(D)J recombination.
Carmona LM, Fugmann SD, Schatz DG.
Genes Dev. 2016 Apr 15;30(8):909-17. doi: 10.1101/gad.278432.116. Epub 2016 Apr 7.

The identification of a novel SIRT6 modulator from Trigonella foenum-graecum using ligand fishing with protein coated magnetic beads.
Singh N, Ravichandran S, Spelman K, Fugmann SD, Moaddel R.
J Chromatogr B Analyt Technol Biomed Life Sci. 2014 Oct 1;968:105-11. doi: 10.1016/j.jchromb.2014.03.016.

Form follows function - the three-dimensional structure of antigen receptor gene loci.
Fugmann SD.
Curr Opin Immunol. 2014 Apr;27:33-7. doi: 10.1016/j.coi.2014.01.011. Epub 2014 Feb 16.

Pharmacophore model of the quercetin binding site of the SIRT6 protein.
Ravichandran S, Singh N, Donnelly D, Migliore M, Johnson P, Fishwick C, Luke BT, Martin B, Maudsley S, Fugmann SD, Moaddel R.
J Mol Graph Model. 2014 Apr;49:38-46. doi: 10.1016/j.jmgm.2014.01.004. Epub 2014 Jan 20.

Synthesis and characterization of a SIRT6 open tubular column: predicting deacetylation activity using frontal chromatography.
Singh N, Ravichandran S, Norton DD, Fugmann SD, Moaddel R.
Anal Biochem. 2013 May 15;436(2):78-83. doi: 10.1016/j.ab.2013.01.018. Epub 2013 Jan 29