Author/Editor		Hancock, John M.; Burns, Roy G.
Title		Specificity and biological significance of microtubule-associated protein-DNA interactions in chick
Type		članek
Vol. and No.		Letnik 927, št. 2
Publication year		1987
Volume		str. 163-169
ISSN		0006-3002 - Biochimica et biophysica acta : International journal of biochemistry and biophysics
Language		eng
Abstract		The interactions between chick brain microtubule associated proteins (MAPs) and chick DNA have been examined using DNA-cellulose chromatography, cross-blotting, and nitrocellulose filter-binding. Comparison of nitrocellulose filter-binding and cross-blotting results show that while MAPs and a minor, Mr 48,000, protein show significant binding at 50 mM NaCl, only the latter continues to bind a significant amount of DNA at 150 mM NaCl, suggesting an ionic basis for the MAP-DNA interactions. MAP-DNA interactions also show weak preference for AT-rich fractions, and are sensitive to S1 nuclease digestion. We suggest that the MAPs bind preferentially to single-stranded DNA. The binding may involve an interaction between the DNA phosphates and the highly cationic tubulin-binding domain of the MAPs. Repetitive fractions of the chick genome prepared both by hydroxyapatite chromatography and by S1 nuclease digestion show binding to a number of minor proteins present in preparations of microtubule proteins, as well as to the MAPs. We conclude that the MAPs probably do not bind specifically to repetitive DNA, in contrast to earlier reports using mouse DNA. MAP-DNA interactions are therefore unlikely to be involved in the attachment of microtubules to mitotic chromosomes.
Keywords		microtubule-associated protein DNA-protein interaction specificity and biological significance beljakovine, povezane z mikrotubulami interakcija DNK-protein specifičnost in biološki pomen