Heat shock p1'otein (Hsp) 40 acts as a co-cha perone of Hsp70 by fac ilitating the ATPase activity of Hsp70 as well as promoting the protein fo lding and rena turation by Hsp70. In the present study. Hsp40 gene was fu sed with a gene f’ragment encoding the HJV-l TAT protein transduction domain(YGRKKRRQRRR) in a bacterial exp1' ession vector pTAT-HA to produce the TAT-fused Hsp40(TAT- Hsp40). Purified TAT-Hsp40 was effectively t 1'ansduced into the HEK 293 cells in a time- and dose-dependent manne1' To examine the effec t of TAT- Hsp40 upon oxidalive stress, HEK293 cells were exposed to H2Û2. Oxidative stress induced the ra pid increase of proteasome activity foll owed by celJ death in HEK 293 cells However ‘ HEK 293 cells t 1'ansduced by TAT- Hsp40 showed r esistance against oxidative st 1'ess induced cytot oxicity, TAT- Hsp40 transduced cell s showed dec1'eased p1'oteasome activity and inhibi ted Hs p70 degradation. These results suggest that Hs p40 rnight protect cell death f rom oxida tive st1'ess by p1'ese1'ving the cellula1' level of Hs p70.

• Sang Gun Ahn(Department of Pathology, School of Dentistry, Chosun University)
• Jung Hoon Yoon(Department of Pathology, School of Dentistry, Chosun University)