TRANSCRIPTION PROPERTIES OF A CELL-TYPE-SPECIFIC TATA-BINDING PROTEIN, TRF

Eukaryotic cells are thought to contain a single TATA-binding protein (TBP) that directs transcription by cellular RNA polymerases. Here we report a cell type-specific TBP-related factor (TRF) that can form a s table TRF/IIA/IIB TATA DNA complex and substitute for TBP in directing RNA polymerase II transcription in vitro. Transfection studies reveal that TRF can differentially mediate activation by some enhancer prote ins but not others. Like TBP, TRF forms a stable complex containing mu ltiple novel subunits, nTAFs. Antibody staining of embryos and polyten e chromosomes reveals cell type-specific expression and gene-selective properties consistent with the shaker/male sterile phenotype of trf m utants. These findings suggest TRF is a homolog of TBP that functions to direct tissue-and gene-specific transcription.