Nucleic Acids Research, 1982, Vol. 10, No. 24 7905-7918
© 1982
MOLECULAR BIOLOGY |
The structure and expression of the preproenkephalin gene
Department of Biochemistry, Imperial College of Science and Technology London SW7 2AZ, UK
Received November 16, 1982. Accepted November 30, 1982.
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 preproenkephal in mRNA encodes four copies of met-enkephalin, two copies of the met-enkephalin extended sequences and one copy of leuenkephalin; 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 hybridization probe to detect the corresponding mRNAs in rat adrenal grand 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.
1Permanent Address: Pituitary Hormone Laboratory, St.Bartholomew's Hospital 51-53 Bartholomew Close, West Smithfield, London ECI