Immunoelectron microscopic localization of ubiquitin in hepatoma cells.
Ubiquitin, a 76 amino acid protein, is covalently attached to abnormal and short-lived proteins, thus marking them for ATP-dependent proteolysis in eukaryotic cells. Free (unconjugated) ubiquitin was localized in hepatoma cells using affinity purified anti-ubiquitin antibodies and colloidal gold immunoelectron microscopy. The anti-ubiquitin antibodies recognize only unconjugated ubiquitin. Ubiquitin is found within the cytoplasm, nucleus, the microvilli, autophagic vacuoles and lysosomes.
Schwartz
A L
AL
Edward Mallinckrodt Department of Pediatrics, Washington University School of Medicine, St Louis, MO 63110.
Ciechanover
A
A
Brandt
R A
RA
Geuze
H J
HJ
D000918:Antibody Specificity; D006528:Carcinoma, Hepatocellular / Q000378:metabolism* / Q000648:ultrastructure; D002451:Cell Compartmentation; D006358:Hot Temperature; D007150:Immunohistochemistry; D008113:Liver Neoplasms; D012995:Solubility; D014407:Tumor Cells, Cultured; D014452:Ubiquitins / Q000378:metabolism*
D014452:Ubiquitins