Synthesis of Preproghrelin Authored: May, B, 2009-06-10 Edited: May, B, 2009-06-10 Pubmed10604470 Pubmed12050285 Pubmed15142980 Pubmed15604212 Pubmed18396350 Pubmed19280057 Pubmed19327128 Reactome Database ID Release 43422088 Reactome, http://www.reactome.org ReactomeREACT_19166 Reviewed: Zhang, Weizhen, 2009-08-29 The ghrelin gene is transcribed and spliced to yield two variants: isoform 1 encodes full-length preproghrelin and isoform 2 encodes des-acyl-Gln14 preproghrelin, which is missing glutamine at position 14 of the mature peptide. Des-acyl-Gln14 ghrelin is found in rodents but is present in negligible quantities in humans. Somatostatin and leptin inhibit ghrelin mRNA levels. Estrogen increases ghrelin mRNA levels. The KLF4 transcription factor binds the ghrelin promoter and activates transcription. Putative binding sites for other transcription factors have been identified but their functions have not been demonstrated. Preproghrelin and prepro-des-Gln14-ghrelin