Apolipoprotein E synthesis in peripheral tissues of nonhuman primates.
The tissue distribution of apolipoprotein (apo) E synthesis in the cynomolgus monkey, Macaca fascicularis, was determined via short-term organ culture with radiolabeled amino acid. Tissue extracts were reacted with antiserum to apo-E, and immunoprecipitates were analyzed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. Newly synthesized apo-E was detected in liver, adrenal, testis, lung, spleen, mesenteric lymph node, and kidney. Peripheral and hepatic apo-E showed the same electrophoretic mobility. High resolution two-dimensional gel analysis showed that newly synthesized apo-E exists in two major isoforms in each tissue examined. Comparison of isoform patterns and mixing experiments showed that newly synthesized apo-E isoforms have identical charge properties in each tissue examined. These data indicate that numerous peripheral tissues synthesize apo-E that is indistinguishable from liver apo-E by the criteria tested. Measurements of relative synthetic capacities illustrate that apo-E is a moderately abundant protein product of a variety of peripheral tissues although quantitative differences in apo-E synthesis occur. Apo-E mRNA from cynomolgus monkey liver and human Hep G2 cells co-migrated with an electrophoretic mobility corresponding to approximately 1200 nucleotides. Apo-E mRNA from liver, brain, thymus, kidney, testis, lymph node, and spleen was the same size. Primer extension analysis yielded a cDNA product representing complete copying of the 5' untranslated region of human Hep G2 apo-E mRNA. A cDNA of identical size was produced with cynomolgus monkey apo-E mRNA from liver, spleen, brain, lymph node, kidney, lung, and thymus. These data suggest that transcription of the apo-E gene is initiated at or near the same site in each tissue examined.
D000302:Adrenal Cortex / Q000378:metabolism; D000818:Animals; D001057:Apolipoproteins E / Q000096:biosynthesis*; D002522:Chlorocebus aethiops; D007163:Immunosorbent Techniques; D007526:Isoelectric Point; D007668:Kidney / Q000378:metabolism; D007700:Kinetics; D008099:Liver / Q000378:metabolism; D008168:Lung / Q000378:metabolism; D008198:Lymph Nodes / Q000378:metabolism; D008252:Macaca fascicularis; D008297:Male; D009924:Organ Culture Techniques; D012333:RNA, Messenger / Q000378:metabolism; D013154:Spleen / Q000378:metabolism; D014018:Tissue Distribution
D001057:Apolipoproteins E; D012333:RNA, Messenger