John C Samuelson, MD, PhD
Professor
Boston University Henry M. Goldman School of Dental Medicine
Molecular & Cell Biology

MD, Harvard Medical School
PhD, Harvard Medical School
BA, Swarthmore College



Our lab studies the glycobiology of protozoan parasites that cause diarrhea (Cryptosporidium and Giardia), dysentery (Entamoeba), birth defects (Toxoplasma), and blindness (Acanthamoeba). In particular, we use mass spectrometric, biochemical, and genetic methods to characterize sugars added to glycoproteins, as well as the enzymes that make or remove these sugars (glycosyltransferases and glycosyl hydrolases, respectively). For example, we showed that asparagine-linked glycans (N-glycans) of Cryptosporidium have a single mannose arm that is hardly modified and so is distinct from complex, highly modified N-glycans of the host. In contrast, Cryptosporidium vaccine candidates have mucin-like domains densely modified with O-GalNAc that resemble host intestinal mucins. We discovered a large set of nuclear proteins of Toxoplasma that are decorated with O-linked fucose and showed that O-fucosyltransferase is a homolog of plant Spindly. The host is lacking Spindly but has an O-GlcNAc transferase with a similar structure to Spindly that modifies an even larger set of nucleocytosolic proteins. We also identified a second Toxoplasma O-fucosyltransferase that modifies a secreted protein MIC2, which is essential for parasite adherence to and invasion into host cells.

The Samuelson lab also studies sugar polymers and glycoproteins present in cyst and oocyst walls of these parasites, which are critical for their transmission from person to person. The simple model we have developed is that these walls contain sugar polymers similar to those in fungal and plant walls: chitin (Entamoeba), glucan (Toxoplasma), and cellulose, chitin, and xylan (Acanthamoeba). In contrast to fungi and plants, glycoproteins in the parasite walls are few and are for the most part lectins (proteins that bind sugars), which bind the sugar polymers. These wall lectins are unique to each parasite and may be targets for diagnostic reagents. Finally, we have explored the potential use of alcohol-based hand sanitizers to prevent transmission of Giardia, Entamoeba, and Acanthamoeba.

Professor
Boston University Chobanian & Avedisian School of Medicine
Virology, Immunology & Microbiology


Faculty
Boston University
National Emerging Infectious Disease Lab


Member
Boston University
Genome Science Institute


Member
Boston University
Bioinformatics Graduate Program


Graduate Faculty (Primary Mentor of Grad Students)
Boston University Chobanian & Avedisian School of Medicine, Graduate Medical Sciences




Decoding the mitochondrial proteomes of six pathogenic protozoa
11/01/2022 - 10/31/2025 (PI)
Howard Hughes Medical Institute


The Biochemistry and Cell Biology of the Spindly O-fucosyltransferase of Toxoplasma
01/01/2020 - 11/30/2024 (PI)
NIH/National Institute of General Medical Sciences
5R01GM129324-04

Structure and development of oocyst and sporocyst walls
08/01/2015 - 01/31/2020 (PI)
NIH/National Institute of Allergy & Infectious Diseases
5R01AI110638-05

Genetic modification of cultured Cryptosporidium to test the autoinfection model
02/01/2017 - 01/31/2019 (PI)
NIH/National Institute of Allergy & Infectious Diseases
5R21AI130889-02

Glycobiology of Giardia
05/01/2011 - 04/30/2017 (PI)
NIH/National Institute of Allergy & Infectious Diseases
5R01AI048082-10

Roles for Beta 1,3-glucan in oocyst walls of Toxoplasma and Eimeria
04/01/2013 - 03/31/2014 (PI)
Mizutani Foundation for Glycosciences


Multiple Lectin Model of the Cyst Wall of Entamoeba
03/01/2000 - 02/28/2013 (PI)
NIH/National Institute of Allergy & Infectious Diseases
5R01AI044070-10



Title


Yr Title Project-Sub Proj Pubs
2023 The Biochemistry and Cell Biology of the SpindlyO-fucosyltransferase of Toxoplasma 5R01GM129324-04
2022 The Biochemistry and Cell Biology of the SpindlyO-fucosyltransferase of Toxoplasma 5R01GM129324-03
2021 The Biochemistry and Cell Biology of the Spindly O-fucosyltransferase of Toxoplasma 5R01GM129324-02
2020 The Biochemistry and Cell Biology of the Spindly O-fucosyltransferase of Toxoplasma 1R01GM129324-01A1
2019 Structure and Development of Oocyst and Sporocyst Walls 5R01AI110638-05 9
2018 Genetic modification of cultured Cryptosporidium to test the autoinfection model 5R21AI130889-02 1
2018 Structure and Development of Oocyst and Sporocyst Walls 5R01AI110638-04 9
2017 Genetic modification of cultured Cryptosporidium to test the autoinfection model 1R21AI130889-01 1
2017 Structure and Development of Oocyst and Sporocyst Walls 5R01AI110638-03 9
2016 Structure and Development of Oocyst and Sporocyst Walls 5R01AI110638-02 9
Showing 10 of 50 results. Show All Results

Publications listed below are automatically derived from MEDLINE/PubMed and other sources, which might result in incorrect or missing publications. Faculty can login to make corrections and additions.

iCite Analysis       Copy PMIDs To Clipboard

  1. Sundararaj BK, Goyal M, Samuelson J. Identification of new targets for the diagnosis of cysts (four) and trophozoites (one) of the eye pathogen Acanthamoeba. bioRxiv. 2024 Oct 17. PMID: 39463995; PMCID: PMC11507896; DOI: 10.1101/2024.10.16.618517;
     
  2. Kanakapura Sundararaj B, Goyal M, Samuelson J. Cellulose binding and the timing of expression influence protein targeting to the double-layered cyst wall of Acanthamoeba. mSphere. 2024 Sep 25; 9(9):e0046624.View Related Profiles. PMID: 39136454; PMCID: PMC11423589; DOI: 10.1128/msphere.00466-24;
     
  3. van der Wel H, Garcia AM, Gas-Pascual E, Willis MM, Kim HW, Bandini G, Gaye MM, Costello CE, Samuelson J, West CM. Spindly is a nucleocytosolic O-fucosyltransferase in Dictyostelium and related proteins are widespread in protists and bacteria. Glycobiology. 2023 Apr 19; 33(3):225-244.View Related Profiles. PMID: 36250576; PMCID: PMC10114647; DOI: 10.1093/glycob/cwac071;
     
  4. Liu L, Veis J, Reiter W, Motari E, Costello CE, Samuelson JC, Ammerer G, Levin DE. Regulation of Pkc1 Hyper-Phosphorylation by Genotoxic Stress. J Fungi (Basel). 2021 Oct 17; 7(10).View Related Profiles. PMID: 34682295; PMCID: PMC8541566; DOI: 10.3390/jof7100874;
     
  5. Bandini G, Agop-Nersesian C, van der Wel H, Mandalasi M, Kim HW, West CM, Samuelson J. The nucleocytosolic O-fucosyltransferase SPINDLY affects protein expression and virulence in Toxoplasma gondii. J Biol Chem. 2020 Nov 23; 296:100039. PMID: 33410402
     
  6. Bandini G, Agop-Nersesian C, van der Wel H, Mandalasi M, Kim HW, West CM, Samuelson J. The nucleocytosolic O-fucosyltransferase SPINDLY affects protein expression and virulence in Toxoplasma gondii. J Biol Chem. 2021 Jan-Jun; 296:100039. PMID: 33158988; PMCID: PMC7949088; DOI: 10.1074/jbc.RA120.015883;
     
  7. Magistrado-Coxen P, Aqeel Y, Lopez A, Haserick JR, Urbanowicz BR, Costello CE, Samuelson J. The most abundant cyst wall proteins of Acanthamoeba castellanii are lectins that bind cellulose and localize to distinct structures in developing and mature cyst walls. PLoS Negl Trop Dis. 2019 05; 13(5):e0007352.View Related Profiles. PMID: 31095564; PMCID: PMC6541295; DOI: 10.1371/journal.pntd.0007352;
     
  8. Bandini G, Albuquerque-Wendt A, Hegermann J, Samuelson J, Routier FH. Protein O- and C-Glycosylation pathways in Toxoplasma gondii and Plasmodium falciparum. Parasitology. 2019 12; 146(14):1755-1766.View Related Profiles. PMID: 30773146; PMCID: PMC6939170; DOI: 10.1017/S0031182019000040;
     
  9. Bandini G, Leon DR, Hoppe CM, Zhang Y, Agop-Nersesian C, Shears MJ, Mahal LK, Routier FH, Costello CE, Samuelson J. O-Fucosylation of thrombospondin-like repeats is required for processing of microneme protein 2 and for efficient host cell invasion by Toxoplasma gondii tachyzoites. J Biol Chem. 2019 02 08; 294(6):1967-1983.View Related Profiles. PMID: 30538131; PMCID: PMC6369279; DOI: 10.1074/jbc.RA118.005179;
     
  10. Gas-Pascual E, Ichikawa HT, Sheikh MO, Serji MI, Deng B, Mandalasi M, Bandini G, Samuelson J, Wells L, West CM. CRISPR/Cas9 and glycomics tools for Toxoplasma glycobiology. J Biol Chem. 2019 01 25; 294(4):1104-1125.View Related Profiles. PMID: 30463938; PMCID: PMC6349120; DOI: 10.1074/jbc.RA118.006072;
     
Showing 10 of 125 results. Show More

This graph shows the total number of publications by year, by first, middle/unknown, or last author.

Bar chart showing 124 publications over 40 distinct years, with a maximum of 8 publications in 1997

YearPublications
19802
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20202
20211
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20242


BU Researchers Join $100 Million Effort to Fight Future Deadly Pathogens

The Brink 2/17/2023

2006-2011 Member of the Pathogenic Eukaryotes study section (2006-2011)
1998-2000 U.S.-India Fund Award (1998-2000)
1994-1996 1994-96 Harvard Digestive Diseases Center Pilot Project (1994-1996)
1993-1995 U.S. Mexico Foundation for Science Award (1993-1995)
1989-1992 American Gastroenterology Association Industry Scholar (1989-1992)
1986-1989 Life Science Research Foundation Fellow (1986-1989)
1984 Harvard Medical School: Shipley Award for best published research
1979-1984 National Institute of Health: Medical Scientist Training Program Fellow (1979-1984)
In addition to these self-described keywords below, a list of MeSH based concepts is available here.

Cryptosporidium
Giardia
Entamoeba
Toxoplasma
Acanthamoeba
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75 E. Newton St Evans Building
Boston MA 02118
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