Keywords: Archaea, N-glycosylation, post-translational modifications, glyco-engineering.

Post-translational protein modifications are responsible for much of the variety and diversity found within the proteome of any organism. Of the various modifications a protein can experience, glycosylation is the most prevalent, occurring either on Asn residues, in the case of N-glycosylation, or on amino acids presenting a functional hydroxyl group, such as Ser or Thr, in the case of O-glycosylation. Both N- and O-glycosylation transpire in all three domains of life, i.e. Eukarya, Bacteria and Archaea, although current understanding of each version of these processes is not consistent. Able to thrive in amongst the harshest environmental conditions on the planet, Archaea express proteins that remain properly folded and functional in the face of physical conditions that would normally lead to protein denaturation, loss of solubility and aggregation. In Archaea, numerous glycoproteins have been detected in a long list of species isolated from a broad range of environments. Analysis of the polysaccharides decorating archaeal proteins reveals the use of a more diverse set of sugar subunits than seen in either eukaryal or bacterial glycoproteins. Still, little is known of the steps or components involved in this post-translational modification in Archaea.

Recent Publications

Elharar, Y., Podilapu, A.R., Guan, Z., Kulkarni, S.S. and Eichler, J. (2017) Assembling glycan-charged dolichol phosphates: Chemoenzymatic synthesis of a Haloferax volcanii N-glycosylation pathway intermediate. Bioconj. Chem., 28, 2461-2470.

Eichler, J. and Imperiali, B. (2018) Stereochemical divergence of polyprenol phosphate glycosyltransferases. Trends in Biochem. Sci., 43, 10-17.

Eichler, J. and Imperiali, B. (2018) Biogenesis of N-linked glycoproteins across domains of life – Similarities and differences. ACS Chem. Biol., 13, 833-837.

Shalev, Y., Soucy, S., Papke, R.T., Gogarten, J.P., Eichler, J., and Gophna, U. (2018) Comparative analysis of surface layer glycoproteins and genes involved in protein glycosylation in the genus Haloferax. Genes, 9,172.

Zaretsky, M., Roine, E. and Eichler. J. (2018) Sialic acid-like sugars in Archaea: Legionaminic acid biosynthesis in the halophile Halorubrum sp. PV6. Front. Microbiol., 9, 2133.

Ph.D. Weizmann Institute of Science, 1994