Soluble Tankyrase Located in Cytosol of Human Embryonic Kidney Cell Line 293

A. N. Kuimov^1* and S. M. Terekhov²

¹Belozersky Institute of Physico-Chemical Biology, Lomonosov Moscow State University, Moscow, 119899 Russia; fax: (095) 939-3181; E-mail: kuimov@genebee.msu.su

²Medico-Genetic Scientific Center, Russian Academy of Medical Sciences, ul. Moskvorech'e 1, Moscow, 115478 Russia

^* To whom correspondence should be addressed.

Received August 27, 2002; Revision received November 11, 2002

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We studied the subcellular localization of tankyrase in primary and immortalized human cell cultures. In embryonic kidney cell line 293 the enzyme was excluded from the nuclei and distributed in fractions of soluble cytosolic proteins and low-density microsomes. Newly revealed cytosolic tankyrase in its poly(ADP-ribosyl)ated form was passed through a Sepharose 2B column and eluted as an apparently monomeric protein. The cytosolic localization of the enzyme correlated with its relatively high activity in the 293 cell line in comparison to eight other studied cell types.

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KEY WORDS: tankyrase, poly(ADP-ribose), ADP-ribosylation

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