Phosphorylated dolichols in aging.
The age-associated changes in the levels and synthesis of dolichyl phosphate and dolichyl diphosphate derivatives were investigated in brain and liver of 057B1/NNia mice. The total chloroform/methanol (2:1, v/v)-extractable phosphorylated dolichols of brain increased from 1.01 micrograms/g at 3 months to 5.22 micrograms/g at 28 months of age. The long-chain dolichyl diphosphate oligosaccharide (Dol-PP-oligo) levels of brain increased from 0.82 microgram/g in 3 months to 2.8 micrograms/g in 28-month-old animals. However, in liver and in kidney, the levels of these components were unaffected by age. Incorporation of labelled glucose from UDP-glucose into dolichyl phosphate glucose and Dol-PP-oligo in brain microsomes was unaffected by age, whereas, in liver microsomes, the rates of synthesis of both components increased by 50-150%. The increased rate of synthesis and lack of accumulation of Dol-PP-oligo in liver suggest an active utilization and/or catabolism of these glycoprotein precursors. The accumulation of Dol-PP-oligo in aging brain may reflect its decreased utilization for N-glycosylation and/or reduced catabolism.
Pullarkat
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New York State Office of Mental Retardation and Developmental Disabilities, Staten Island 10314.
Pullarkat
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PS
Morris
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D000375:Aging / Q000378:metabolism*; D000818:Animals; D001921:Brain / Q000378:metabolism; D002851:Chromatography, High Pressure Liquid; D002855:Chromatography, Thin Layer; D004288:Dolichol Phosphates / Q000378:metabolism; D004286:Dolichols / Q000378:metabolism*; D006023:Glycoproteins / Q000096:biosynthesis; D051379:Mice; D008810:Mice, Inbred C57BL; D008861:Microsomes / Q000378:metabolism; D008862:Microsomes, Liver / Q000378:metabolism; D010766:Phosphorylation; D013056:Spectrophotometry, Ultraviolet
D004288:Dolichol Phosphates; D004286:Dolichols; D006023:Glycoproteins; C028306:dolichol monophosphate; C026406:dolichol pyrophosphate