Biologically active peptides encoded by small open reading frames

Hundreds of thousands of short open reading frames (sORFs) that are potentially capable of coding peptides containing up to 100 amino acids are found in the genomes of all living organisms. The known sORF-encoded peptides perform such important functions as regulation of morphogenesis in insects, control of embryogenesis in fish, involvement in the process of formation of nitrogen-fixing nodules in plants, and others. However, the coding potential of most sORFs, as well as the number of such peptides in cells, is almost completely unknown. A systematic approach based on the use of bioinformatics algorithms, as well as transcriptional and proteomic profiling, makes it possible to identify sORFs and analyze their coding potential. In this review, we discuss the issues of transcription and translation of sORFs in cells, the features of their search and identification, as well as the analysis of biological functions.