Biochemical characterization of Yin Yang 1-RNA complexes.

YY1 (Yin Yang 1) is present in the Xenopus oocyte cytoplasm as a constituent of messenger ribonucleoprotein complexes (mRNPs). Association of YY1 with mRNPs requires direct RNA-binding activity. Previously, we have shown YY1 has a high affinity for U-rich RNA; however, potential interactions with plausible in vivo targets have not been investigated.

Porcine adenovirus type 3 E1B large protein downregulates the induction of IL-8.

Replication-defective (E1-E3 deleted) adenovirus vector based gene delivery results in the induction of cytokines including IL-8, which may contribute to the development of inflammatory immune responses. Like other adenoviruses, E1 + E3 deleted porcine adenovirus (PAdV) 3 induces the production of IL-8 in infected cells. In contrast, no IL-8 production could be detected in cells infected with wild-type or mutant PAdV-3s containing deletion in E1A + E3 (PAV211) or E1Bsmall + E3 (PAV212).

Nucleic acids exert a sequence-independent cooperative effect on sequence-dependent activation of Toll-like receptor 9.

Toll-like receptor 9 (TLR9) activates the innate immune system in response to microbial DNA or mimicking oligodeoxynucleotides. Although cell stimulation experiments demonstrate the preferential activation of TLR9 by CpG-containing nucleic acids, direct binding investigations have reached contradictory conclusions with respect to the ability of this receptor to bind nucleic acids in a sequence-specific manner. To address this apparent discrepancy, we report the purification of the soluble ectodomain of human TLR9 with characterization of its ligand binding properties.

The Yin Yang 1 transcription factor associates with ribonucleoprotein (mRNP) complexes in the cytoplasm of Xenopus oocytes.

Yin Yang 1 (YY1) is a multifunctional transcription factor that activates, represses, or initiates transcription of a diverse assortment of genes. Previous studies suggest a role for YY1 in cellular growth and differentiation, but its biological function during development of the vertebrate oocyte or embryo remains to be determined. We recently showed that YY1 is abundantly expressed throughout oogenesis and early embryonic stages of Xenopus, but it is sequestered in the cytoplasm and does not function directly in transcriptional regulation.