The co-translational addition of N-linked oligosaccharide chains is critical for the proper folding, intracellular translocation and function of many membrane glycoproteins mediating essential neurobiological functions in the central nervous system (CNS). Because of the importance of this modification, the long-term goal of this project has been to understand the role of ER proteins in the regulation of biosynthesis of dolichyl phosphate (Dol-P), the assembly of Glc3Man9GlcNAc2-P-P-dolichol and the transbilayer movement of dolichyl-phospho-saccharide intermediates in brain. This application proposes five Specific Aims using biochemical and genetic approaches designed to: 1) isolate and learn more about the structures of ER proteins mediating the transverse diffusion of Man-P-Dol, Glc-P-Dol and ManSGlcNAc2 P-P-Dol in brain using a novel and promising transport assay with water-soluble analogues; 2) use biochemical and genetic approaches in a topological study of the assembly of a membrane-anchored mannan in M. luteus as a model system for membrane proteins involved in the synthesis and transbilayer movement of mannolipid intermediates in the ER in brain; 3) clone cDNAs that encode the long-chain cis-isoprenyltransferase (cis- IPTase) and dolichol kinase, two enzymes involved in the de novo biosynthesis of Dol-P in the CNS. These cloned cDNAs will provide coding sequence information and probes to be used to assess developmental changes in the expression of cis-IPTase and dolichol kinase in embryonic rat brain cultures and LPS-activated murine B cells; 4) isolate a temperature-sensitive mutant for dolichol kinase to test the hypothesis that this enzyme catalyzes the terminal step in the de novo pathway for Dol-P biosynthesis and 5) to extend the study of a new development in isoprenoid biosynthesis by investigating the enzymatic mechanism by which farnesol (F-OH) and geranylgeraniol (GG-OH) are converted to the """"""""activated"""""""" isoprenyl donors, farnesyl pyrophosphate (F-P-P) and geranylgeranyl pyrophosphate (GG-P-P) , respectively in brain.

Agency
National Institute of Health (NIH)
Institute
National Institute of General Medical Sciences (NIGMS)
Type
Research Project (R01)
Project #
5R01GM036065-16
Application #
6385610
Study Section
Pathobiochemistry Study Section (PBC)
Program Officer
Marino, Pamela
Project Start
1981-06-01
Project End
2004-09-29
Budget Start
2001-09-30
Budget End
2002-09-29
Support Year
16
Fiscal Year
2001
Total Cost
$318,560
Indirect Cost
Name
University of Kentucky
Department
Biochemistry
Type
Schools of Medicine
DUNS #
832127323
City
Lexington
State
KY
Country
United States
Zip Code
40506
Rush, Jeffrey S (2015) Role of Flippases in Protein Glycosylation in the Endoplasmic Reticulum. Lipid Insights 8:45-53
Harrison, Kenneth D; Park, Eon Joo; Gao, Ningguo et al. (2011) Nogo-B receptor is necessary for cellular dolichol biosynthesis and protein N-glycosylation. EMBO J 30:2490-500
Rush, Jeffrey S; Alaimo, Cristina; Robbiani, Riccardo et al. (2010) A novel epimerase that converts GlcNAc-P-P-undecaprenol to GalNAc-P-P-undecaprenol in Escherichia coli O157. J Biol Chem 285:1671-80
Rush, Jeffrey S; Gao, Ningguo; Lehrman, Mark A et al. (2009) Suppression of Rft1 expression does not impair the transbilayer movement of Man5GlcNAc2-P-P-dolichol in sealed microsomes from yeast. J Biol Chem 284:19835-42
Hartman, Matthew C T; Jiang, Songmin; Rush, Jeffrey S et al. (2007) Glycosyltransferase mechanisms: impact of a 5-fluoro substituent in acceptor and donor substrates on catalysis. Biochemistry 46:11630-8
Rush, Jeffrey S; Waechter, Charles J (2006) Partial purification of mannosylphosphorylundecaprenol synthase from Micrococcus luteus: a useful enzyme for the biosynthesis of a variety of mannosylphosphorylpolyisoprenol products. Methods Mol Biol 347:13-30
Pakkiri, Leroy S; Waechter, Charles J (2005) Dimannosyldiacylglycerol serves as a lipid anchor precursor in the assembly of the membrane-associated lipomannan in Micrococcus luteus. Glycobiology 15:291-302
Rush, Jeffrey S; Waechter, C J (2005) Assay for the transbilayer movement of polyisoprenoid-linked saccharides based on the transport of water-soluble analogues. Methods 35:316-22
Rush, Jeffrey S; Waechter, C J (2004) Functional reconstitution into proteoliposomes and partial purification of a rat liver ER transport system for a water-soluble analogue of mannosylphosphoryldolichol. Biochemistry 43:7643-52
Fernandez, F; Rush, J S; Toke, D A et al. (2001) The CWH8 gene encodes a dolichyl pyrophosphate phosphatase with a luminally oriented active site in the endoplasmic reticulum of Saccharomyces cerevisiae. J Biol Chem 276:41455-64

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