Functions of O-glycans: In collaboration with the Ten Hagen lab (NIH), Stasia Anderson, Daryl Despres and M Starost (NIH), we have continued studies on the cardiac phenotypes resulting from the deletion of GalNAc-T1. We have found that the heart valves are markedly enlarged in the affected hearts. We are analyzing the underlying molecular cause(s) for this phenotype. Tom Beres in collaboration with the Angerer lab (NIH), examined the roles of GalNAc-Ts and mucin-type O-glycosylation during embryonic development of the sea urchin, S. purpuratus. Two phenotypes are being characterized in morphants in which GalNAc-T7 expression is ablated. One phenotype involves the loss of muscle, and the other, embryos lack both the ciliated band (cells with cilia that sweep food into the mouth) and the network of nerves normally present in this region. Raul Rojas, using confocal microscopy, has 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. We have a series of collaborations with investigators around the world to assess/phenotype various mouse models in which the expression of specific GalNAcTs have been ablated. This includes work with A.G. Holleboom and J.A. Kuivenhoven on the role of GalNAc-T2 on the control of lipids, and with Q. Zheng on the function of GalNAc-T2 on otitis media. Mechanisms of GalNAcT function: We are collaborating with L. Masgrau to use the hybrid QM/MM (quantum mechanics/molecular mechanics) approach to study the retaining mechanism used by GalNAc-Ts in forming O-glycans.

Project Start
Project End
Budget Start
Budget End
Support Year
3
Fiscal Year
2014
Total Cost
Indirect Cost
Name
Dental & Craniofacial Research
Department
Type
DUNS #
City
State
Country
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

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