REGULATED SPLICING OF THE OCT-2 TRANSCRIPTION FACTOR RNA IN NEURONAL CELLS

The primary RNA transcript derived from the gene encoding the Oct-2 tr anscription factor is alternatively spliced to yield a number of diffe rent mRNAs which encode different isoforms of this protein. The mRNAs encoding two such isoforms Oct-2c and mini Oct-2 were originally detec ted in neuronal cells. We show here that the mRNAs encoding these form s also occur in other tissues with the proportion of the mini Oct-2 mR NA being much higher in the spleen than in the brain. However, the lev els of the mini Oct-2 mRNA increase in neuronal cell lines in response to differentiation-inducing stimuli and decrease upon exposure to gro wth factors. Hence the splicing of the Oct-2 transcript can be regulat ed in both a tissue specific manner and in neuronal cells in response to specific stimuli. The significance of this effect is discussed in t erms of the differing ability of different forms of Oct-2 to activate or inhibit gene expression.