Microprotein-Encoding RNA Regulation in Cells Treated with Pro-inflammatory and Pro-Fibrotic Stimuli (RNA-Seq colon cell lines)

Recent analysis of the human proteome via proteogenomics and ribosome profiling of the transcriptome revealed the existence of thousands of previously unannotated microprotein-coding small open reading frames (smORFs). Most functional microproteins were chosen for characterization because of their evolutionary conservation. However, one example of a non-conserved immunomodulatory microprotein in mice suggests that strict sequence conservation misses some intriguing microproteins. Here, we examine the ability of gene regulation to identify human microproteins with potential roles in inflammation or fibrosis of the intestine. To do this, we collected ribosome profiling data of intestinal cell lines and peripheral blood mononuclear cells (PBMCs), and then used gene expression of microprotein-encoding transcripts to identify strongly regulated microproteins, including several examples of microproteins that are only conserved with primates. This approach reveals a number of new microproteins worthy of additional functional characterization, and provides a dataset that can be queried in different ways to find additional gut microproteins of interest. RNA-sequencing of samples from four colon-related cell lines (HCEC-1CT, Caco-2, CCD-18Co, PBMC), each subjected to treatment with individual pro-inflammatory molecules