Expression of the human immunodeficiency virus type 1 ( HIV ) protease in cultured cells leads to apoptosis , preceded by cleavage of bcl-2 , a key negative regulator of cell death .
expression of the human immunodeficiency virus type 1 ( hiv ) protease in cultured cells leads to apoptosis , preceded by cleavage of bcl-2 , a key negative regulator of cell death .
O O O B-virus I-virus I-virus I-virus I-virus O B-virus O O O B-cell_line I-cell_line O O B-other_name O O O O O B-protein_molecule O O O O O O O O O