The primary objective of the proposal is to elucidate the roles of O-glycan core 2 branchings in development, formation of selectin ligands, and the control of glycosylation in normal and tumor cells. In the past few years, the investigators have made critical progress in this field. First, they have cloned cDNAs encoding core 2 and I beta-1,6-N- acetylglucosaminyltransferases which form beta-1,6-N- acetylglucosaminyl branches. The primary structure of these two enzymes revealed that they are homologous to each other in their catalytic domains. Second, they demonstrated that the formation of poly-N-acetyllactosaminyl repeats and sialyl Lex in O-glycans are entirely dependent on branches formed by the core 2 beta-1,6-N-acetylglucosaminyltransferase, core 2 GnT. Third, they discovered that the formation and disappearance of core 2 branches are closely associated with thymocyte differentiation. Based on these findings, four major areas for further study are proposed as follows: 1) Elucidation of roles of core 2 GnT in presentation of selectin ligands. They will study the expression of O-glycan sialyl Lex directed by core 2 GnT and determine the roles of such structures and carrier glycoproteins in presentation of ligands for E- and P-selectins. 2) Elucidation of the role of core 2 branching in embryonic development. The studies will determine the roles of core 2 branched O-glycans in mouse development by ectopic expression, and systematic and tissue- specific knock- out of core 2 GnT gene. 3) Subcellular localization of core 2 GnT and its role in the control of glycosylation. The studies will determine the subcellular localization of core 2 GnT and evaluate its effect on the control of glycosylation by the manipulation of its subcellular localization. 4) Isolation of core 4 GnT gene and its expression in normal and cancerous colon cells. They will isolate core 4 GnT gene, which is related to the core 2 GnT gene and determine the roles of core 2 GnT and core 4 GnT in glycosylation of normal and cancerous colon cells. These studies will allow us to understand the physiological roles of core 2- based O-glycans during development and oncogenesis.

Agency
National Institute of Health (NIH)
Institute
National Cancer Institute (NCI)
Type
Method to Extend Research in Time (MERIT) Award (R37)
Project #
5R37CA033000-17
Application #
2442940
Study Section
Pathology B Study Section (PTHB)
Project Start
1982-01-01
Project End
2000-06-30
Budget Start
1997-07-01
Budget End
1998-06-30
Support Year
17
Fiscal Year
1997
Total Cost
Indirect Cost
Name
Sanford-Burnham Medical Research Institute
Department
Type
DUNS #
009214214
City
La Jolla
State
CA
Country
United States
Zip Code
92037
Kobayashi, Motohiro; Hoshino, Hitomi; Suzawa, Kenichi et al. (2012) Two distinct lymphocyte homing systems involved in the pathogenesis of chronic inflammatory gastrointestinal diseases. Semin Immunopathol 34:401-13
Hoshino, Hitomi; Tsuchida, Akiko; Kametani, Kiyokazu et al. (2011) Membrane-associated activation of cholesterol ?-glucosyltransferase, an enzyme responsible for biosynthesis of cholesteryl-?-D-glucopyranoside in Helicobacter pylori critical for its survival. J Histochem Cytochem 59:98-105
Lee, Seung Ho; Yu, Shin-Yi; Nakayama, Jun et al. (2010) Core2 O-glycan structure is essential for the cell surface expression of sucrase isomaltase and dipeptidyl peptidase-IV during intestinal cell differentiation. J Biol Chem 285:37683-92
Mitoma, Junya; Fukuda, Minoru (2010) Core O-glycans required for lymphocyte homing gene knockout mice of core 1 beta1,3-N-acetylglucosaminyltransferase and core 2 N-acetylglucosaminyltransferase. Methods Enzymol 479:257-70
Wang, Huan; Tang, Rong; Zhang, Weiyu et al. (2009) Core2 1-6-N-glucosaminyltransferase-I is crucial for the formation of atherosclerotic lesions in apolipoprotein E-deficient mice. Arterioscler Thromb Vasc Biol 29:180-7
Kobayashi, Motohiro; Lee, Heeseob; Nakayama, Jun et al. (2009) Roles of gastric mucin-type O-glycans in the pathogenesis of Helicobacter pylori infection. Glycobiology 19:453-61
Stone, Erica L; Ismail, Mohd Nazri; Lee, Seung Ho et al. (2009) Glycosyltransferase function in core 2-type protein O glycosylation. Mol Cell Biol 29:3770-82
Kobayashi, Motohiro; Fukuda, Minoru; Nakayama, Jun (2009) Role of sulfated O-glycans expressed by high endothelial venule-like vessels in pathogenesis of chronic inflammatory gastrointestinal diseases. Biol Pharm Bull 32:774-9
Kobayashi, Motohiro; Lee, Heeseob; Nakayama, Jun et al. (2009) Carbohydrate-dependent defense mechanisms against Helicobacter pylori infection. Curr Drug Metab 10:29-40
Lee, Seung Ho; Hatakeyama, Shingo; Yu, Shin-Yi et al. (2009) Core3 O-glycan synthase suppresses tumor formation and metastasis of prostate carcinoma PC3 and LNCaP cells through down-regulation of alpha2beta1 integrin complex. J Biol Chem 284:17157-69

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