Antibodies against chromosomal HMG proteins stain the cytoplasm of mammalian cells

Cell. 1979 Jan;16(1):181-9. doi: 10.1016/0092-8674(79)90199-5.


Antibodies specific to protein HMG-1 were purified by affinity chromatography on Sepharose columns to which HMG-1 was covalently bound. Immunofluorescence studies with these antibodies reveal that HMG-1 or components which immunologically cross-react with HMG-1 are present in the cytoplasm of Chinese hamster V-79, rat liver TR-12 and bovine trachea EBTr-NBL-4 cells. At selected antibody concentrations, the fluorescence present in the cytoplasm is more intense than that observed in the nucleus. The presence of HMG-1 protein in the cytoplasm of rat liver cells was verified by direct examination of the protein content of selected cytoplasmic fractions. A protein with electrophoretic mobility identical to HMG-1 was detected by electrophoresis on polyacrylamide gels containing either sodium dodecylsulfate or urea. Furthermore, the cytoplasmic extracts yielded a positive complement fixation with anti-HMG-1, while no reaction was obtained with control anti-H1 sera. We suggest that HMG protins, rather than functioning in the nucleus alone, are important structural elements of the entire cell.

MeSH terms

  • Animals
  • Antibodies / isolation & purification
  • Cell Nucleus / metabolism
  • Chromatography, Affinity
  • Chromosomal Proteins, Non-Histone / metabolism*
  • Cytoplasm / metabolism*
  • Fluorescent Antibody Technique
  • Liver / ultrastructure
  • Rats


  • Antibodies
  • Chromosomal Proteins, Non-Histone