Overexpression of hsp70i facilitates reactivation of intracellular proteins in neurones and protects them from denaturing stress

Transfection of neurones with an adenoviral vector (Ad) expressing high lev els of hsp70i was shown to protect primary hippocampal cultures from heat s tress. To investigate one of the molecular mechanisms which may underlie hs p70i's neuroprotective effects we measured luciferase activity in the prese nce and absence of hsp70i following heat or chemical inactivation. Lucifera se activity was recovered to 80% of control levels in the presence of recom binant hsp70i in vitro. Luciferase activity was also maintained in primary hippocampal neurones exposed to a denaturing stress if transfected with Ad- hsp70i. These results support the hypothesis that hsp70i protects neurones from stress hy interacting with cytosolic proteins and thereby protecting t hem from inactivation. (C) 1998 Federation of European Biochemical Societie s.