Section on Biological Chemistry
Principal Deputy Director, NIH
Lab: Building 30, Room 524
NIH Office: Building 1, Room 126
Bethesda, MD 20892-2290
Dr. Lawrence Tabak's laboratory studies the functions and biosynthesis of O-glycans. Mucin-glycoproteins are heavily decorated with carbohydrate side-chains, termed O-glycans, which are often clustered within repeating amino acids sequences of the protein (tandem repeats). Functionally, membrane-bound mucins are involved in signal transduction events, whereas secreted mucins contribute to the formation of extracellular matrix or to the gel-like mucus coat which envelopes mucosal surfaces of the body thereby forming the most exterior face of the innate immune system. Although it is known that O-glycans are ubiquitous among proteins, the precise nature of the “O-glycome” remains to be defined. We have approached this by both top-down and bottom-up proteomic studies as well as investigations of the substrate specificities of the multi-gene family of enzymes that are responsible for the formation of O-glycans, the UDP-GalNAc:polypeptide N-Acetylgalactosaminyltransferases (GalNAcTs).
Dr. Lawrence Tabak is the principal deputy director of NIH, a position he has held since August 23, 2010. Dr. Tabak served as NIDCR acting director from January 1, 2020 to October 13, 2020 and as the acting principal deputy director of NIH from November 2008 through August 2009. Named as the director of NIDCR in September 2000, he held that post through August 2010. Prior to joining NIH, Dr. Tabak served as the senior associate dean for research and professor of dentistry and biochemistry & biophysics in the School of Medicine and Dentistry at the University of Rochester in New York. A former NIH MERIT recipient, Dr. Tabak has received several honors and awards for his work including election to membership in the Institute of Medicine of the National Academies. He has also received teaching awards for his work with both graduate and medical students.
Herbomel GG, Rojas RE, Tran DT, Ajinkya M, Beck L, Tabak LA. The GalNAc-T Activation Pathway (GALA) is not a general mechanism for regulating mucin-type O-glycosylation. PLoS One, 12(7):e0179241. doi: 10.1371/journal.pone.0179241. eCollection 2017
Famiglietti AL, Wei Z, Beres TM, Milac AL, Tran DT, Patel D, Angerer RC, Angerer LM, Tabak LA. Characterization and expression analysis of Galnts in developing Strongylocentrotus purpuratus embryos. PLoS One. 2017 Apr 27;12(4): e0176479
- Revoredo L, Wang S, Bennett EP, Clausen H, Moremen KW, Jarvis DL, Ten Hagen KG, Tabak LA, Gerken TA. 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. 2016 Apr;26(4):360-76.
- Tian E, Stevens SR, Springer DA, Anderson SA, Starost MF, Patel V, Ten Hagen KG, Tabak LA. Galnt1 is required for normal heart valve development and cardiac function. PLoS One. 2015 Jan 23;10(1):e0115861.
- Gomez H, Rojas R, Patel D, Tabak LA, Lluch J, Masgrau L. A computational and experimental study of O-glycosylation. Catalysis by human UDP- GaINac polypeptide: GaINac transferase-T2. Org Biomol Chem. 2014 May 7;12(17):2645-55.
- Bennett, E.P., Mandel, U., Clausen, H., Gerken, T.A., Fritz, T.A., and Tabak, L.A. Control of Mucin-Type O-Glycosylation – A Classification of the Polypeptide GalNAc-transferase Gene Family, Glycobiology (2011)22:736-756, 2012.
- Holleboom AG, Karlsson H, Lin RS, Beres TM, Sierts JA, Herman DS, Stroes ESG, Aerts JM, Kastelein JJP, Motazacker MM, Dallinga-Thie GM, Levels JHM, Zwinderman AH, Seidman JG, Seidman CE, Ljunggren S, Lefeber DJ, Morava E, Wevers RA, Fritz TA, Tabak LA, Lindahl M, Hovingh GK, and Kuivenhoven JA. Heterozygosity for a loss-of-function mutation in GALNT2 improves plasma triglyceride clearance in man. Cell Metab. 2011 Dec 7;14(6):811-8
- Gerken TA, Jamison O, Perrine CL, Collette JC, Moinova H, Ravi L, Markowitz SD, Shen W, Patel H, Tabak LA. Emerging paradigms for the initiation of mucin type protein O-glycosylation by the polypeptide GalNAc transferase (ppGalNAc T) family of glycosyltransferases. J Biol Chem. 2011 Apr 22;286(16):14493-507.
- Tabak LA. The role of mucin-type O-glycans in eukaryotic development. Semin Cell Dev Biology. 2010 Aug;21(6):616-21.
- Miwa HE, Gerken TA, Jamison O, Tabak LA. Isoform-specific O-glycosylation of osteopontin and bone sialoprotein by polypeptide N-acetylgalactosaminyltransferase-1. J. Biol. Chem., 2010 Jan 8;285(2):1208 –19.
- Perrine, CL, Ganguli, A, Wu, P, Bertozzi, CR, Fritz,TA, Raman, J, Tabak, LA and TA Gerken. Glycopeptide-preferring polypeptide GalNAc transferase 10 (ppGalNAc T10), involved in mucin-type O-glycosylation, has a unique GalNAc-O-Ser/Thr-binding site in its catalytic domain not found in ppGalNAc T1 or T2. J. Biol. Chem. 2009 Jul 24;284(30):20387-97.