title: Evidence for thyrotropin-releasing hormone (TRH) biosynthesis in rat prostate.
abstract: TRH occurs in very high concentration in rat prostate. A species specific protein with repetitive -Gln-His-Pro-Gly- sequences, which are flanked on the N- and C-terminus by paired basic residues, has been shown to be the source of TRH in frog skin and rat hypothalamus. Following cleavage by trypsin-like enzymes, the peptide fragments with N-terminal Gln spontaneously cyclize to pGlu while Gly within the C-terminally extended peptides serves as the -NH2 donor for the alpha-amidation of the proline residue. Because this last step in the biosynthesis of TRH is rate limiting for pGlu-His-Pro-Gly, we have combined several chromatographic and radioimmunoassay techniques to identify this TRH precursor in rat prostate.
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D003429:Cross Reactions; D008297:Male; D011467:Prostate / Q000378:metabolism*; D011498:Protein Precursors / Q000032:analysis / Q000096:biosynthesis; D011761:Pyrrolidonecarboxylic Acid / Q000031:analogs & derivatives; D011863:Radioimmunoassay; D051381:Rats; D011919:Rats, Inbred Strains; D013973:Thyrotropin-Releasing Hormone / Q000031:analogs & derivatives / Q000032:analysis / Q000096:biosynthesis*; D014357:Trypsin / Q000378:metabolism
chemical_list: D011498:Protein Precursors; D013973:Thyrotropin-Releasing Hormone; C040476:thyrotropin-releasing hormone, Gly; C046418:pro-thyrotropin releasing hormone; D014357:Trypsin; D011761:Pyrrolidonecarboxylic Acid