Interaction of Keratin K1 with Nucleic Acids on the Cell Surface

B. P. Chelobanov^1*, P. P. Laktionov¹, M. V. Kharkova¹, E. Yu. Rykova¹, D. V. Pyshnyi¹, I. A. Pyshnaya¹, K. Marcus², H. E. Meyer², and V. V. Vlassov¹

¹Novosibirsk Institute of Bioorganic Chemistry, Siberian Branch of the Russian Academy of Sciences, pr. Akad. Lavrentieva 8, Novosibirsk 630090, Russia; fax: 7 (383-2) 33-3677; E-mail: chelobanov@niboch.nsc.ru

²Ruhr-Universitat Bochum, Zentrum fur Klinische Forschung, Universitatsstrasse 150, D-44780 Bochum, Germany; fax: +49 234 32-14554; E-mail: Helmut.E.Meyer@ruhr-uni-bochum.de

^* To whom correspondence should be addressed.

Received October 18, 2002; Revision received January 22, 2003

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The interaction of surface proteins from A431 cells and cellular extracts with nucleic acids was investigated using affinity modification with ³²P-labeled reactive oligonucleotide derivatives. Proteins with molecular weights of 68, 46, 38, and 28 kD as well as several low molecular weight proteins capable of binding to nucleic acids were found on the surface of intact cells. It was demonstrated that a protein with molecular weight of 68 kD is exposed at the cell surface, since the treatment of cells with trypsin results in the cleavage of this protein. Disruption of the integrity of the cell membrane (scrapping, treatment with trypsin, or permeabilization of the cell membrane with streptolysin O or saponin) disrupts the interaction of the reactive oligonucleotides with the cell surface proteins. Affinity modification of the cytosolic and membrane-cytosolic cell fractions with labeled oligonucleotides results in the modification of a large number of proteins, where proteins with molecular weights of 68, 46, 38, and 28 kD can be found as minor components. Surface oligonucleotide-binding proteins with molecular weight of ~68 kD were isolated by affinity chromatography after the modification of intact A431 cells with a reactive oligonucleotide derivative. The isolated surface oligonucleotide-binding proteins from A431 cells were sequenced, and one of the proteins was identified as keratin K1.

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KEY WORDS: oligonucleotides, oligonucleotide binding proteins, nucleic acid receptors, affinity modification, keratin K1

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