Fibronectin: a chromatin-associated protein?

Luciano Zardi, Annalisa Siri, Barbara Carnemolla, Leonardo Santi, William D. Gardner, Sallie O. Hoch

Research output: Contribution to journalArticle

Abstract

We have previously reported that chromatin preparations from human cultured fibroblasts contain a single homologous serum protein. In this paper we present evidence, based on immunological identity and physicochemical properties, that this serum protein is fibronectin. Furthermore, using a radioimmunoassay system, we have estimated that fibronectin represents about 0.7% of the total protein in both chromatin preparations and whole fibroblasts. Using a nitrocellulose filter assay system, we also show that fibronectin is a DNA-binding protein having an equilibrium constant of 4.6 × 10-6 M. Equilibrium competition experiments have demonstrated that fibronectin has the ability to differentiate among nucleotides, indicating that fibronectin-DNA interaction is at least partially specific, and that a minimum polymer length of 12-18 nucleotides is required for effective binding to occur. Fibronectin has been isolated readily from plasma using DNA-affinity chromatography. We do not have direct evidence that fibronectin is an actual nonhistone chromosomal protein, but fibronectin is a DNA-binding protein (at least under in vitro assay conditions) and appears to be a normal constituent of chromatin as chromatin is currently isolated from cell nuclei.

Original languageEnglish
Pages (from-to)649-657
Number of pages9
JournalCell
Volume18
Issue number3
DOIs
Publication statusPublished - 1979

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ASJC Scopus subject areas

  • Cell Biology
  • Molecular Biology
  • Medicine(all)

Cite this

Zardi, L., Siri, A., Carnemolla, B., Santi, L., Gardner, W. D., & Hoch, S. O. (1979). Fibronectin: a chromatin-associated protein? Cell, 18(3), 649-657. https://doi.org/10.1016/0092-8674(79)90120-X