MRNAs Associated with the Sam68 RNA Binding Protein

The Src associated substrate in mitosis of 68kDa, Sam68, is an RNA-binding protein that belongs to the KH domain family of proteins. KH-type RNA binding proteins are known to mediate high affinity RNA binding and regulate RNA metabolism including pre-mRNA splicing, mRNA export and protein translation. The RNA binding specificity of Sam68 as well as its RNA targets are poorly understood. Herein we cross-linked mRNA associated with Sam68 and identified some of the mRNA associated with the Sam68 RNA binding protein complex. By using this strategy, we have identified 23 mRNAs that are associated with the immunoprecipitated endogenous Sam68 protein complex. Five of the identified mRNAs were validated by co-immunoprecipitation assay followed by reverse transcription PCR confirming that we had indeed identified mRNAs associated with the Sam68 protein complex.