RNA immunoprecipitation to identify RHA-binding transcripts in HEK293 cells

Given that RHA regulates translation by binding a PCE located at the 5’ UTR of the target transcripts a genome-wide screen was performed to identify mRNAs that bind RHA in vivo. The results from four experiments with samples obtained in four independent RNA immunoprecipitations identified 375 transcripts that co-immunoprecipitate with FLAG RHA. Since N-terminal FLAG tagged RHA specifically co-immunoprecipitates PCE-containing mRNAs HEK293 cells were transfected with a CMV-FLAG-RHA construct. Cytoplasmic lysates were immunoprecipitated with anti-FLAG beads. RNA was extracted from the immunoprecipitate and used to probe a human Agilent expression arrays. An immunoprecipitation with cells transfected with empty FLAG plasmid was used as negative control.