The Y-box-binding protein (YBX1), family of cold shock proteins, is multifunctional and appears to regulate gene expression at both the transcriptional and posttranscriptional levels. Transcriptional targets for YBX1 includes genes associated with cell death, cell death associated receptor and tumor suppressor genes. YBX1 also up regulates genes associated with cell proliferation. YBX1 is also implicated to have an important role in inducing drug resistance on tumor cells. YBX1 binds RNAs sequence specific manner and interacts with splicing factors and plays important role in mRNA splicing and translation. Recent study suggested that competition between YBX1 and eIF4G for mRNA binding is required for efficient stimulation of eIF4F activity by PABP.
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.