DIFFERENTIAL MESSENGER-RNA EXPRESSION OF PHOSPHOLIPASE-D (PLD) ISOZYMES DURING CAMP-INDUCED DIFFERENTIATION IN C6 GLIOMA-CELLS

GTP gamma S-dependent phospholipase D (PLD) activity time-dependently increased during differentiation of rat C6 glioma cells to astrocytic phenotypes induced by dibutyryl cyclic AMP (dbcAMP)/theophylline. The changes in PLD mRNA level wen examined by reverse transcriptase-polyme rase chain reaction (RT-PCR) method using the degenerate primers desig ned based on two conserved amino acid sequences in PLDs of human and y east. The amplified three DNA fragments (tentatively termed as rPLDa, b, and c) contained the conserved regions present in PLDs of various o rganisms. RT-PCR using non-degenerate primers showed that rPLDa mRNA i ncreased within 12h following treatment with dbcAMP, reaching a broad plateau and then returned to the initial level at 48h. In contrast, th e level of rPLDb mRNA showed a concurrent decrease. rPLDc decreased in a lime-dependent manner, These results suggest that the expression of PLD mRNAs are differentially regulated during differentiation in C6 g lioma cells. (C) 1996 Academic Press, Inc.