| Liquid beta galactosidase assay and coimmunoprecipitation experiments revealed that the strength of the interaction between USP 7 and ataxin 1 is influenced by the length of the polyglutamine tract in the ataxin 1 ; weaker interaction was observed in mutant ataxin 1 with longer polyglutamine tract and USP 7 was not recruited to the mutant ataxin 1 aggregates in the Purkinje cells of SCA 1 transgenic mice . 0.93694371^^^ USP 7 , a ubiquitin specific protease , interacts with ataxin 1 , the SCA 1 gene product . 0.82525194^^^ Using the yeast two hybrid system , we have found that USP 7 , a ubiquitin specific protease , binds to ataxin 1 . 0.62251523^^^ |