DOWN-REGULATION OF MAP KINASE-ACTIVITY SIGNALED BY HIV-1-GP120 COAT PROTEIN IN GRANULAR NEURONS AND GLIAL-CELLS FROM RAT CEREBELLUM

me have studied the effect of gp120 coat protein from HIV-1 on tyrosin e phosphorylation processes in primary cultures of granular neurons or glial cells from the cerebellum of neonatal rats. The extracellular a pplication of recombinant gp120 (200 pM) was able to reduce the phosph otyrosine content and the immunoreactivity for active form-specific an tibodies of MAP kinase. Whereas in neurons MAP kinase appeared to be t he only protein whose phosphotyrosine content was decreased, in glial cultures the inhibitory effect of gp120 on tyrosine phosphorylation pr ocesses appeared to be more widespread. In neuronal cultures, the effe ct of the viral protein was prevented by the concomitant treatment wit h depolarizing agents. (C) 1997 Academic Press.