Mucin-type O-glycosylation is an evolutionarily conserved protein modification found across most eukaryotic species. This form of post-translational modification is initiated by a family of enzymes (ppGalNAc-Ts or GalNAc-Ts in mammals) that catalyze the initial addition of an N-Acetylgalactosamine (GalNAc) sugar onto the hydroxyl group of serine or threonine residues. There are 20 GalNAc-Ts in humans and 18 in mice. The differential tissue and substrate specificities of these enzymes suggest unique roles for each in the organs and tissues where they are expressed. I am utilizing real-time fluorescent imaging techniques to elucidate the importance of O-glycosylation in secretion and correlative light and electron microscopy (CLEM) to determine the localization of individual transferases during various biological processes.
Tran D.T., Masedunskas A., Weigert R., and Ten Hagen K.G. Arp2/3-mediated F-actin formation controls regulated exocytosis in vivo. Nat. Commun. 6:10098 doi: 10.1038/ncomms10098 (2015).
News and Views: Merrifield C.J. Actin puts the squeeze on Drosophila glue secretion. Nat Cell Biol. 18, 142-144, doi:10.1038/ncb3305 (2016).
Tran D.T., and Ten Hagen K.G. Mucin-type O-glycosylation during development. J Biol Chem. 2013 Mar 8;288(10):6921-9.
Tran D.T., Lim J.M., Liu M, Stalnaker S.H., Wells L., Ten Hagen K.G., and Live D. Glycosylation of ·-dystroglycan: O-mannosylation influences the subsequent addition of GalNAc by UDP-GalNAc polypeptide N-acetylgalactosaminyltransferases. J Biol Chem. 2012 Jun 15;287(25):20967-74.
Tran, D.T., Zhang, L., Zhang, Y., Tian, E, Earl, LA., and Ten Hagen, K.G. Multiple members of the UDP:GalNAc:polypeptide N-acetylgalactosaminyltransferase family are essential for viability in Drosophila. J Biol Chem. 2012 Feb 17;287(8):5243-52.