Subcellular distribution of apolipoprotein E along the lipoprotein synthetic pathway of rat liver

Conference · Sat Mar 01 00:00:00 EST 1986 · Fed. Proc., Fed. Am. Soc. Exp. Biol.; (United States)

OSTI ID:5450298

Cole, T G; Stockhausen, D C

Apolipoprotein E (apoE) is synthesized by the liver and is secreted as a component of VLDL. To define the intracellular locations of apoE, liver from 10 nonfasted male rats were removed and subcellular organelles prepared by differential pelleting through sucrose gradients. Mass of apoE was measured by radioimmunoassay. Approximately 10% of total hepatic apoE was recovered in rough endoplasmic reticulum (RER), smooth endoplasmic reticulum (SER) and Golgi fractions. Concentrations of apoE (ng/mg protein) were: homogenate, 302 +/- 59; RER, 653 +/- 251; SER, 1250 +/- 471; Golgi, 11,044 +/- 4291. Total apoE content of each reaction (..mu..g/organelle) was: homogenate (whole liver), 517 +/- 103; RER, 15 +/- 3; SER, 9 +/- 3; Golgi, 28 +/- 8. These data indicate that along the putative pathway of lipoprotein synthesis (RER->SER->Golgi), apoE concentration increases in each successive organelle and that flux of apoE is apparently most rapid through SER. Furthermore, the majority of apoE in the rat liver is apparently not directly associated with the lipoprotein synthetic pathway and may be associated with internalized lipoproteins or may be involved in non-lipoprotein related functions.

• Research Organization: Washington Univ. School of Medicine, St. Louis, MO
• OSTI ID: 5450298
• Report Number(s): CONF-8604222-; TRN: 86-028418
• Journal Information: Fed. Proc., Fed. Am. Soc. Exp. Biol.; (United States), Vol. 45:3; Conference: 70. annual meeting of the Federation of American Society for Experimental Biology, St. Louis, MO, USA, 13 Apr 1986
• Country of Publication: United States
• Language: English

Related Subjects

59 BASIC BIOLOGICAL SCIENCES
APOLIPOPROTEINS
METABOLISM
TISSUE DISTRIBUTION
BIOLOGICAL PATHWAYS
ENDOPLASMIC RETICULUM
LIVER
RADIOIMMUNOASSAY
RADIOISOTOPES
RATS
ANIMALS
BODY
CELL CONSTITUENTS
DIGESTIVE SYSTEM
DISTRIBUTION
GLANDS
IMMUNOASSAY
IMMUNOLOGY
ISOTOPE APPLICATIONS
ISOTOPES
LIPIDS
LIPOPROTEINS
MAMMALS
ORGANIC COMPOUNDS
ORGANOIDS
ORGANS
PROTEINS
RADIOASSAY
RADIOIMMUNOLOGY
RODENTS
TRACER TECHNIQUES
VERTEBRATES
550501* - Metabolism- Tracer Techniques