The structure and expression of the preproenkephalin gene.
Enkephalins are pentapeptides with opioid activity which are found in a wide variety of tissues. Studies of enkephalin-containing peptides from the adrenal gland have established that the mature pentapeptides are derived by proteolytic processing of a precursor protein. We have shown that human adrenal medullary tumours contain mRNA which can be translated in vitro to yield a single major enkephalin precursor. The sequence of cloned cDNA shows that the preproenkephalin mRNA encodes four copies of met-enkephalin, two copies of met-enkephalin extended sequences and one copy of leu-enkephalin; each copy is flanked by paired basic amino acids which are presumably recognised by the processing protease. We have used the cloned human cDNA as a hybridisation probe to detect the corresponding mRNAs in rat adrenal gland and, in smaller amounts, in rat brain. We have been unable to detect in brain any other cross-hybridising mRNAs which might encode other putative precursor proteins.
D000310:Adrenal Gland Neoplasms / Q000235:genetics; D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D003001:Cloning, Molecular; D004247:DNA / Q000378:metabolism; D004745:Enkephalins / Q000235:genetics*; D004926:Escherichia coli / Q000235:genetics; D005796:Genes; D006801:Humans; D010957:Plasmids; D014176:Protein Biosynthesis; D011498:Protein Precursors / Q000235:genetics*; D012333:RNA, Messenger / Q000235:genetics; D011817:Rabbits; D012156:Reticulocytes / Q000378:metabolism; D014158:Transcription, Genetic
D004745:Enkephalins; D011498:Protein Precursors; D012333:RNA, Messenger; D004247:DNA; C033660:preproenkephalin