A 70-KDA TO 80-KDA GLIAL-CELL PROTEIN INTERACTS WITH THE AGGGAAGGGA DOMAIN OF THE JC VIRUS EARLY PROMOTER ONLY IN THE PRESENCE OF THE NEIGHBORING CIS DNA ELEMENTS

The neurotropic virus JC (JCV) causes the demyelinating disease progre ssive multifocal leukoencephalopathy. JCV is transcriptionally regulat ed by both positive and negative cis elements. Previous studies have s hown that the AGGGAAGGGA sequence, in isolation, interacts with a 53- to 56-kDa cellular protein and acts as a silencer for the late promote r. We have reexamined the role of the AGGGAAGGGA element in the glial cell-specific transcriptional regulation of JCV by studying it in a lo nger natural context of elements of the JCV early promoter. Transcript ional analysis in C6 glial cells of selectively mutated AGGGAAGGGA dom ains within the nt 98-153 region of the JCV early promoter revealed th at both GGG regions in the AGGGAAGGGA sequence are required for glial cell-specific transcription. The interactions of cellular proteins wit h the AGGGAAGGGA domain were also found to be dependent upon the prese nce or absence of neighboring cis elements. The TATA region was found to facilitate the interaction of specific proteins with the AGGGAAGGGA domain. Domain-specific photocrosslinking studies revealed the bindin g of a glial cell protein of approximately 70-80 kDa to the AGGGAAGGGA domain only when it was flanked by its neighboring cis elements, the TATA and NF-1 domains of the JCV promoter. (C) 1994 Academic Press, In c.