[Bovine protein kinase C isotypes transduced into Molt-4/HIV-1 cells augment the expression of HIV-1 genome]

Protein kinase C (PKC) is known to be an ubiquitous enzyme found in a variety of mammalian tissue and has been shown to require Ca2+ and phospholipid, and to be further activated by diacylglycerol, which increased the affinity of the kinase for both Ca2+ and phospholipid. PKC is composed with a family of multiple isotypes with closely related structures, although the detailed functions of each isotype have not yet been clarified. We tried to clarify the difference of biological functions among the isotypes of PKC. Three PKC isotypes (alpha, beta 1, gamma) were purified from bovine brain by L-threonine-Sepharose affinity column, and fractions containing alpha and beta 1 forms (Peak A) and gamma form (Peak B) were obtained. Each peak integrated into erythrocytic ghost was transduced into cells persistently infected with HIV-1 (Molt-4/HIV-1) by fusion method. Peak A containing PKC alpha and beta 1 isotypes induced TNF-alpha production, HIV-1 cDNA titer and P24 antigen in culture of Molt-4/HIV-1 cells, but Peak B containing PKC gamma did not show any effects on Molt-4/HIV-1 cells. The effect of PKC alpha and beta 1 on the production of TNF-alpha and the augmentation of HIV-1 replication are inhibited by both anti-TNF-alpha antibody and staurosporine, a potent PKC inhibitor.