| Northern blot analysis showed that testis contains higher levels of HSJ 2 mRNA than other tissues examined , and the expression pattern of HSJ 2 mRNA in postnatal rat testis is similar to PTTG . ^^^ In vitro binding assays demonstrated that both S 10 and HSJ 2 bind to PTTG specifically and that PTTG can be co immunoprecipitated with S 10 and HSJ 2 from transfected cells . ^^^ |