Pip, a novel IRF family member, is a lymphoid-specific, PU.1-dependent transcriptional activator.

摘要: The immunoglobulin light-chain gene enhancers E kappa 3', lambda 2-4, and 3-1 contain a conserved cell type-specific composite element essential for their activities. This binds B cell-specific heterodimeric protein complex that consists of the Ets family member PU.1 second factor (NF-EM5), whose participation in formation is dependent on presence DNA-bound PU.1. In this report we describe cloning characterization Pip (PU.1 interaction partner), lymphoid-specific most likely NF-EM5. As expected, only PU.1; furthermore, ternary critically phosphorylation at serine-148. expressed specifically lymphoid tissues both B- T-cell lines. When coexpressed NIH-3T3 cells, function as mutually transcription activators element. amino-terminal DNA-binding domain exhibits high degree homology to domains members interferon regulatory (IRF) family, which includes IRF-1, IRF-2, ICSBP, ISGF3 gamma.