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PubMed · 519752

Fibronectin: a chromatin-associated protein?

L Zardi·A Siri·B Carnemolla·L Santi·W D Gardner·S O Hoch
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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 x 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.

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Antibody SpecificityChromatinCross ReactionsDNAFibronectinsHumansJournal ArticleResearch Support, U.S. Gov't, P.H.S.

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BibTeXRIS

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

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