Abstract

The general aim of this research is to delineate the various steps in the glycosylation of proteins and to determine possible biological consequences of impaired glycosylation. Our approach is to isolate and characterize mammalian cell mutants defective in glycosylation. Chinese hamster ovary (CHO) cell mutants are isolated by both single and multistep selection procedures and by screening procedures. Once isolated, the enzymatic defect in the cell line is determined, allowing us to catalog various reactions in the synthetic pathway; subsequently, we can determine what effect the alteration in a particular reaction has on different glycoprotein products. For example, we previously determined that the defect in B4-2-1, a CHO cell line isolated by Dr. April R. Robbins, NIH, was the lack of mannosylphosphoryldolichol synthase activity. This cell line had been isolated on the basis of its altered mannose 6-phosphate receptor activity; this receptor is a glycoprotein. Recently, we have also shown that B4-2-1 lacks mannosylphosphorylretinol synthase activity, strongly implying that there is only one synthase that utilizes either dolichyl or retinyl phosphate as substrate. (A)

  Funding Agency

Agency
National Institute of Health (NIH)
Institute
National Cancer Institute (NCI)
Type
Research Project (R01)
Project #
5R01CA020421-11
Application #
3165284
Study Section
Pathobiochemistry Study Section (PBC)
Project Start
1976-12-01
Project End
1988-06-30
Budget Start
1986-12-01
Budget End
1988-06-30
Support Year
11
Fiscal Year
1987
Total Cost
Indirect Cost

  Institution

Name
Johns Hopkins University
Department
Type
Schools of Public Health
DUNS #
045911138
City
Baltimore
State
MD
Country
United States
Zip Code
21218

  Publications

Acosta-Serrano, Alvaro; O'Rear, Jessica; Quellhorst, George et al. (2004) Defects in the N-linked oligosaccharide biosynthetic pathway in a Trypanosoma brucei glycosylation mutant. Eukaryot Cell 3:255-63
Pu, Lixia; Scocca, Jane R; Walker, Brian K et al. (2003) A single point mutation resulting in an adversely reduced expression of DPM2 in the Lec15.1 cells. Biochem Biophys Res Commun 312:555-61
Pu, Lixia; Scocca, Jane R; Walker, Brian K et al. (2003) The divergent 5' ends of DPM2 mRNAs originate from the alternative splicing of two adjacent introns: characterization of the hamster DPM2 gene. Biochem Biophys Res Commun 312:817-24
Cacan, R; Duvet, S; Labiau, O et al. (2001) Monoglucosylated oligomannosides are released during the degradation process of newly synthesized glycoproteins. J Biol Chem 276:22307-12
O'Rear, J L; Scocca, J R; Walker, B K et al. (1999) Chinese hamster ovary cells with reduced hexokinase activity maintain normal GDP-mannose levels. J Cell Biochem 72:56-66
Quellhorst Jr, G J; O'Rear, J L; Cacan, R et al. (1999) Nonglucosylated oligosaccharides are transferred to protein in MI8-5 Chinese hamster ovary cells. Glycobiology 9:65-72
Kaiden, A; Rosenwald, A G; Cacan, R et al. (1998) Transfer of two oligosaccharides to protein in a Chinese hamster ovary cell B211 which utilizes polyprenol for its N-linked glycosylation intermediates. Arch Biochem Biophys 358:303-12
Duvet, S; Labiau, O; Mir, A M et al. (1998) Cytosolic deglycosylation process of newly synthesized glycoproteins generates oligomannosides possessing one GlcNAc residue at the reducing end. Biochem J 335 ( Pt 2):389-96
Krag, S S (1998) The importance of being dolichol. Biochem Biophys Res Commun 243:1-5
Quellhorst Jr, G J; Piotrowski, J S; Steffen, S E et al. (1998) Identification of Schizosaccharomyces pombe prenol as dolichol-16,17. Biochem Biophys Res Commun 244:546-50

Showing the most recent 10 out of 31 publications