We have collaborated with the Angerer lab (NIH) to examine the roles of GalNAc-Ts and mucin-type O-glycosylation during embryonic development of the sea urchin, S. purpuratus. One phenotype has been characterized in morphants in which SpGalNAc-T13 expression was attenuated. This results in a deficiency of embryonic skeleton and neurons, suggesting that mucin-type O-glycans play essential roles during embryonic development in S. purpuratus. A manuscript will be submitted shortly. Gaetan Herbomel, Duy Tran, Raul Rojas, Monica Ajinkya, and Lauren Beck challenged the hypothesis put forward by Gill et al., (The Journal of Cell Biology. 189:843, 2010) that growth factors EGF or PDGF, induce Golgi complex-to- endoplasmicreticulum (ER) relocation of both GalNAc-Ts and Tn antigen in HeLa cells,offering a mechanism for Tn antigen over-expression termed GALA. However, we were unable to reproduce these findings. Upon treatment of HeLa cells with either EGF or PDGF we observed no change in the co-localization of endogenous GalNAc-T1, GalNAc-T2 or Tn antigen with the Golgi complex marker TGN46. There was also no enhancement of localization with the ER marker calnexin. We conclude that growth factors do not cause redistribution of GalNAc-Ts from the Golgi complex to the ER in HeLa cells.We have placed a manuscript on the BioRxiv pre-print server (http://biorxiv.org/content/early/2016/08/23/071225) and have submitted the manuscript to JCB. Duy Tran, Gaetan Herbomel, Raul Rojas, and Jessi Becker are evaluating the studied the targeting signals in GalNAc-Ts that direct these enzymes from the endoplasmic reticulum to the Golgi and then retain them in the Golgi. They are also using super resolution microscopy to discern which compartments in the Golgi different GalNAc-Ts are retained in. Nadine Samara and Amy Fernandez are studying the structural basis for GalNAc-T substrate specificity using X-ray crystallography. We have a collaboration with Henrik Clausen in Denmark on the role of GalNAc-T11 in early mouse development.

Project Start
Project End
Budget Start
Budget End
Support Year
Fiscal Year
Total Cost
Indirect Cost
Dental & Craniofacial Research
Zip Code
Ji, Suena; Samara, Nadine L; Revoredo, Leslie et al. (2018) A molecular switch orchestrates enzyme specificity and secretory granule morphology. Nat Commun 9:3508
Becker, Jessica L; Tran, Duy T; Tabak, Lawrence A (2018) Members of the GalNAc-T family of enzymes utilize distinct Golgi localization mechanisms. Glycobiology 28:841-848
Herbomel, Gaetan G; Rojas, Raul E; Tran, Duy T et al. (2017) The GalNAc-T Activation Pathway (GALA) is not a general mechanism for regulating mucin-type O-glycosylation. PLoS One 12:e0179241
Famiglietti, Amber L; Wei, Zheng; Beres, Thomas M et al. (2017) Characterization and expression analysis of Galnts in developing Strongylocentrotus purpuratus embryos. PLoS One 12:e0176479
Revoredo, Leslie; Wang, Shengjun; Bennett, Eric Paul et al. (2016) Mucin-type O-glycosylation is controlled by short- and long-range glycopeptide substrate recognition that varies among members of the polypeptide GalNAc transferase family. Glycobiology 26:360-76
Tian, E; Stevens, Sharon R; Guan, Yu et al. (2015) Galnt1 is required for normal heart valve development and cardiac function. PLoS One 10:e0115861
Raman, Jayalakshmi; Guan, Yu; Perrine, Cynthia L et al. (2015) Erratum: UDP-N-acetyl-?-D-galactosamine: polypeptide N-acetylgalactosaminyltransferases: completion of the family tree. Glycobiology 25:465
Gómez, Hansel; Rojas, Raúl; Patel, Divya et al. (2014) A computational and experimental study of O-glycosylation. Catalysis by human UDP-GalNAc polypeptide:GalNAc transferase-T2. Org Biomol Chem 12:2645-55
Gerken, Thomas A; Revoredo, Leslie; Thome, Joseph J C et al. (2013) The lectin domain of the polypeptide GalNAc transferase family of glycosyltransferases (ppGalNAc Ts) acts as a switch directing glycopeptide substrate glycosylation in an N- or C-terminal direction, further controlling mucin type O-glycosylation. J Biol Chem 288:19900-14
Patterson, Amy P; Tabak, Lawrence A; Fauci, Anthony S et al. (2013) Research funding. A framework for decisions about research with HPAI H5N1 viruses. Science 339:1036-7

Showing the most recent 10 out of 16 publications