Pancreatic hormone (PP) [ (PUBMED:6107857) ] is a peptide synthesized in pancreatic islets of Langherhans, which acts as a regulator of pancreatic and gastrointestinal functions.
The hormone is produced as a larger propeptide, which is enzymatically cleaved to yield the mature active peptide: this is 36 amino acids in length [ (PUBMED:3031687) ] and has an amidated C terminus [ (PUBMED:2599092) ]. The hormone has a globular structure, residues 2-8 forming a left-handed poly-proline-II-like helix, residues 9-13 a beta turn, and 14-32 an alpha-helix,held close to the first helix by hydrophobic interactions [ (PUBMED:3031687) ]. Unlike glucagon, another peptide hormone, the structure of pancreatic peptide is preserved in aqueous solution [ (PUBMED:2067973) ]. Both N and C termini are required for activity: receptor binding and activation functions may reside in the N and C termini respectively [ (PUBMED:3031687) ].
Pancreatic hormone is part of a wider family of active peptides that includes:
Neuropeptide Y (NPY or melanostatin) [ (PUBMED:3031687) ], one of the most abundant peptides in the mammalian nervous system. NPY is implicated in the control of feeding and the secretion of the gonadotrophin-releasing hormone.
Peptide YY (PYY) [ (PUBMED:6953409) ]. PPY is a gut peptide that inhibits exocrine pancreatic secretion, has a vasoconstrictory action and inhibits jejunal and colonic mobility. Known as goannatyrotoxin-Vere1 in the venom of the pygmy desert monitor lizard (Varanus eremius) where it has a triphasic action: rapid biphasic hypertension followed by prolonged hypotension in prey animals [ (PUBMED:20631207) ].
Neuropeptide F (NPF) from invertebrates such as worms and snail.
Skin peptide Tyr-Tyr (SPYY) from the frog Phyllomedusa bicolor. SPYY shows a large spectra of antibacterial and antifungal activity.
Polypeptide MY (peptide methionine-tyrosine). A regulatory peptide from the intestine of the sea lamprey (Petromyzon marinus) [ (PUBMED:2070789) ].
All these peptides are 36 to 39 amino acids long. Like most active peptides, their C-terminal is amidated and they are synthesized as larger protein precursors.
Multiple receptors for the pancreatic polypeptide (PP-fold) family: physiological implications.
Proc Soc Exp Biol Med. 1998; 218: 7-22
Display abstract
The pancreatic polypeptide (PP-fold) family of peptides consists of the endocrine peptides, pancreatic polypeptide (PP) and peptide YY (PYY), and the neuroneally derived peptide, neuropeptide Y (NPY). All three peptides are found in the circulation, with PP found primarily in the pancreas and PYY found principally in the gut. NPY is released into the circulation from neuroneal stores in response to stress. These peptides have broad peripheral actions on a number of organs. Not surprisingly, PYY and PP are believed to play an important role in the function of the gastrointestinal tract while NPY is a potent vasconstrictor and may have effects on the gut through the enteric nervous system. In the brain, NPY has been implicated in anxiety and depression, feeding and obesity, memory retention, neuroneal excitability, endocrine function, and metabolism. Recent advances in the molecular biology of the receptors for these peptides have resulted in the identification of at least six receptor subtypes with varying peptide pharmacology. Compared to other G-protein coupled receptor families, the PP-fold peptide receptors exhibit a relatively low level of sequence identity. Further advances in the development of selective agonists and antagonists for individual receptor subtypes will be needed to understand further their role in physiological function.
Hormone families: pancreatic hormones and homologous growth factors.
Nature. 1980; 287: 781-7
Display abstract
The growing realization that biologically active polypeptides can be grouped in families, the members of which show structural and functional relatedness, is illustrated by the four families which are represented in the pancreas by the hormones insulin, glucagon, somatostatin and pancreatic polypeptide.
Metabolism (metabolic pathways involving proteins which contain this domain)
This information is based on mapping of SMART genomic protein database to KEGG orthologous groups. Percentage points are related to the number of proteins with PAH domain which could be assigned to a KEGG orthologous group, and not all proteins containing PAH domain. Please note that proteins can be included in multiple pathways, ie. the numbers above will not always add up to 100%.
