Figure 6.

Small t augments c-Jun and CREB transactivation in JEG-3 cells. (A) The GAL4-c-Jun construct (1.2 μg) was transfected with the small t expression plasmids (600 ng) and the (UAS)₅E1BTATALUC reporter (4.8 μg) in JEG-3 cells. The mean data (± SEM) of n separate transfections are shown. (Comparison is shown normalized for the effect of dl888). (B Inset) An electrophoretic mobility-shift assay was performed with the cyclin D1 CRE/ATF site using nuclear extracts from JEG-3 cells, with the addition of specific antibodies as described. The arrow indicates the primary complex formed and the asterisk indicates the supershifted complex formed with the CREB/CREM antibody HM93. (B) The GAL4-CREB construct (1.2 μg) was transfected with the small t expression plasmid (600 ng) and (UAS)₅E1BTATALUC (4.8 μg) either alone or with the addition of an expression plasmid for wild-type or mutant protein kinase A catalytic subunit (C).