A brief introduction of Micro Peptide For over a long period it was assumed that the length of protein coding was somewhere 100AA. Beside, the algorithms for finding the coding sequence that has a very short open reading frame (ORF) length are not very reliable since they can be lost in pile of junk ORF which is formed by chance. However, in the recent past many non canonical genes were discovered in different organisms as Arabidopsis, Saccharomyces, and Drosophila.
RNA acts as a template for cellular proteins in the protein synthesis where it transfers RNA (tRNA) as ribosomal. However, a better share of eukaryotic transcripts is called ncRNAs. A good number of these contain short open reading frames (sORFs). This is one of the most obvious reasons that they are named ncRNAs. The ncRNAs and LncRNAs are coded for something after all. There are evidences found that there are regions that encode short polypeptide. Biochemists have known for many years that short polypeptides have an important physiological role to play in the quality peptide formation. Processing and development of the larger polypeptides, by cleaving them in shorter version is established across biochemical phenomenon. To make it more understandable, there is a famous example called proopiomelanocortin protein (POMC). The POMC is processed to make several important biologically active Quality peptides. POMC can be enzymatically cleaved into different peptide like N-Terminal Peptide of Proopiomelanocortin (NPP, or pro-γ-MSH), γ-Melanotropin (γ-MSH), Corticotropin (Adrenocorticotropic Hormone, or ACTH), α-Melanotropin (α-Melanocyte-Stimulating Hormone, or α-MSH), Corticotropin-like Intermediate Peptide (CLIP), β-Lipotropin (β-LPH), Lipotropin Gamma (γLPH), β-Melanotropin (β-MSH), β-Endorphin, and [Met]Enkephalin.
By this example we can understand that bioactive small peptides come from the precursor proteins or peptides which have signal sequences where N-terminal ends. It goes under modification, the proteolysis through a secretory pathway. These peptides have difficult functioning. The small peptides which are encoded in the short opening reading frames does not constitute or lack signaling sequences and are simply released into cytoplasm. However, one thing which needs to be considered here is that short peptides are intercellular exchanged is rare at the moment. Research group in England and Japan have studied the cause of mutation in gene called pri (for “polished rice”) or tarsal-less (tal) in Drosophila or milli-pattes (mlpt) in Tribolium and later the results were published in Journal called PLoS Biology and Science.