Acta Biologica 42. (1991)

1-3. szám - A. Azaryan–G. Dovanjyan–A. Lajtha: Stress-induced change in cerebral ATP+ubiquitin-dependent proteinase activity vary with age

Acta Biologica Hungarica 42(1-3), pp. 297-300 (1991) STRESS-INDUCED CHANGE IN CEREBRAL ATP+UBIQUITIN-DEPENDENT PROTEINASE ACTIVITY VARY WITH AGE* A. AZARYAN1, G. DOVANJYAN1 , A. LA3THA2 ^Institute of Biochemistry, Yerevan, USSR 2Center for Neurochemistry, Ward's Island, New York, USA (Accepted: 1991-01-21) Stress-induced changes in cerebral ATP+ubiquitin-dependent proteinase activity were studied and the effect of age on it was checked. For that purpose 23 000 g supernacant prepared from whole brain of 3- and 7-month-old rats after 6h long immobil­ization stress were used. With azocasein as substrate, at pH 8.0 values of ATP+ubi­­quitin-dependent proteinase activity increased for 20% and 10% in 3- and 7-month-old animals respectively. Following 24 h long immobilization, values of cerebral ATP+ubi­quitin-dependent activity in 3-month-old animals dropped by 16%. Data obtained indi­cate that immobilization stress affects ATP+ubiquitin-dependent proteinase activity and point to the contribution of age in the modulation of enzyme response to stress. Keywords : Stress, ubiquitin, proteolysis, heat shock proteins, ATP+ubiquitin­­dependent proteinase Introduction ATP+ubiquitin-dependent proteinase (UCDEN) is a component of cyto­solic ubiquitin(Ub)-dependent proteolysis system and ubiquitination of proteins is thought to target proteins for degradation /5, 6, 12/. Cerebral UCDEN has been recently characterized /1/. The enzyme is present in the nerve cells and is located mainly in the cytosol /1/. The extent of par­ticipation of UCDEN activity in protein turnover in the brain has not been XPresented during the Satellite Syfnposium to the 20th Meeting of FEBS, Mechanism and Regulation of Intracellular Protein Catabolism", August 26-29, 1990, Dobogókő, Hungary Send offprint requests to: Dr. A. Azaryan, Institute of Biochemistry, P. Sevak Str. 5/1, Yerevan 375044, USSR Akadémiai Kiadó, Budapest

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