Small Open Reading Frames: Tiny Treasures of the Non-coding Genomic Regions
Open Reading Frames (ORFs) are the DNA sequences in thegenome that has the potential to be translated. Generally,only long ORFs greater than or equal to 300 nucleotides or nt) are thought to beprotein coding regions and are considered as genes in thegenome annotation pipeline. Until recent years, small ORFs(smORFs) of less than 100 codons (less than 300 nt) were regarded asnon-functional on the basis of empirical observations. However,recent work on ribosome profiling and mass spectrometryhave led to the discovery of many translating functionalsmall ORFs and presence of their stable peptide products.Further, examples of biologically active peptides with vitalregulatory functions underline the importance of smORFsin cell functions. Genome-wide analysis shows that smORFsare conserved across diverse species, and the functional characterizationof their peptides reveals their critical role in abroad spectrum of regulatory mechanisms. Further analysisof small ORFs is likely throw light on many exciting, unexploredregulatory mechanisms in different developmentalstages and tissue types.
Volume 26 | Issue 10