IGF2BP3/IMP3 is identical to the KH domain containing protein overexpressed in cancer (KOC). The protein encoded by this gene was found to bind in vivo to IGF2 leader 3 and leader 4 mRNAs and H19 RNA. Binding of IMP3 to the 5' UTR of the IGF2 leader 3 mRNA represses translation of IGF2 during late development. The encoded protein contains several KH domains, which are important for RNA binding and are known to be involved in RNA synthesis and metabolism. A pseudogene exists on chromosome 7, and there are putative pseudogenes on other chromosomes. The growth regulating gene IMP3 has been characterized as a candidate for Silver-Russell syndrome.
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.