Mammalian Staufen1 (Stau1) is a ubiquitous double-stranded RNA binding protein associated with polysomes. It has two protein isoforms, molecular weights of 55 and 63 kDa. The 55 kDa isoform associates with 40S and 60S ribosomal subunit and colocalizes with the rough endoplasmic reticulum. Stau1 is thought to function in transporting mRNA, controlling and eliciting mRNA decay. Previous study showed that the Stau1 recruits upf1 to 3’ UTR region of Arf1 mRNA and induces the Stau1-mediated mRNA decay (SMD). Recent study suggests that Stau1 regulates divers class of mammalian transcripts. In order to identify mRNA targets of Staufen proteins, RIP-Assay technology was employed and identified distinct but overlapping subset of cellular mRNAs associated with Stau1 and Stau2-containing ribonucleoprotein complexes.
Posttranscriptional regulation of gene expression is a ribonucleoprotein-driven process, which involves RNA binding proteins (RBPs) and non-coding RNAs that affect splicing, nuclear export, subcellular localization, mRNA decay and translation. The RNP Immunoprecipitation-Chip (RIP-Chip), RIP-Seq and RIP-RTPCR allow the identification of multiple RNA targets of RBPs globally and within the context of a cell extract. Antibodies specific to the RNA binding protein of interest are used to co-immunoprecipitate the RNA binding protein and the associated subset of mRNAs. The mRNA content is interrogated using standard microarray or sequencing technology. RIP-Certified Antibody is validated for use in RNP Immunoprecipitation (RIP) in conjunction with the RIP-Assay Kit distributed from MBL. Its ability to immunoprecipitate mRNAs and RBPs complex was confirmed by quantitative and qualitative analysis on NanoDrop, Bioanalyzer and RT-PCR or microarray.