title: Human cathepsin V protease participates in production of enkephalin and NPY neuropeptide neurotransmitters.
abstract: Proteases are required for processing precursors into active neuropeptides that function as neurotransmitters for cell-cell communication. This study demonstrates the novel function of human cathepsin V protease for producing the neuropeptides enkephalin and neuropeptide Y (NPY). Cathepsin V is a human-specific cysteine protease gene. Findings here show that expression of cathepsin V in neuroendocrine PC12 cells and human neuronal SK-N-MC cells results in production of (Met)enkephalin from proenkephalin. Gene silencing of cathepsin V by siRNA in human SK-N-MC cells results in reduction of (Met)enkephalin by more than 80%, illustrating the prominent role of cathepsin V for neuropeptide production. In vitro processing of proenkephalin by cathepsin V occurs at dibasic residue sites to generate enkephalin-containing peptides and an ∼24-kDa intermediate present in human brain. Cathepsin V is present in human brain cortex and hippocampus where enkephalin and NPY are produced and is present in purified human neuropeptide secretory vesicles. Colocalization of cathepsin V with enkephalin and NPY in secretory vesicles of human neuroblastoma cells was illustrated by confocal microscopy. Furthermore, expression of cathepsin V with proNPY results in NPY production. These findings indicate the unique function of human cathepsin V for producing enkephalin and NPY neuropeptides required for neurotransmission in health and neurological diseases.
authors.affiliation: Skaggs School of Pharmacy and Pharmaceutical Sciences, University of California, San Diego, California 92093, USA.
authors.forename: Lydiane
authors.initials: L
authors.lastname: Funkelstein
authors.forename: W Douglas
authors.initials: WD
authors.lastname: Lu
authors.forename: Britta
authors.initials: B
authors.lastname: Koch
authors.forename: Charles
authors.initials: C
authors.lastname: Mosier
authors.forename: Thomas
authors.initials: T
authors.lastname: Toneff
authors.forename: Laurent
authors.initials: L
authors.lastname: Taupenot
authors.forename: Daniel T
authors.initials: DT
authors.lastname: O'Connor
authors.forename: Thomas
authors.initials: T
authors.lastname: Reinheckel
authors.forename: Christoph
authors.initials: C
authors.lastname: Peters
authors.forename: Vivian
authors.initials: V
authors.lastname: Hook
mesh_terms: D000368:Aged; D000595:Amino Acid Sequence; D000818:Animals; D015153:Blotting, Western; D002403:Cathepsins / Q000235:genetics / Q000378:metabolism*; D045744:Cell Line, Tumor; D002540:Cerebral Cortex / Q000201:enzymology; D002837:Chromaffin Granules / Q000201:enzymology; D003546:Cysteine Endopeptidases / Q000235:genetics / Q000378:metabolism*; D004745:Enkephalins / Q000235:genetics / Q000378:metabolism*; D006624:Hippocampus / Q000201:enzymology; D006801:Humans; D008297:Male; D018613:Microscopy, Confocal; D008969:Molecular Sequence Data; D009478:Neuropeptide Y / Q000378:metabolism*; D018377:Neurotransmitter Agents / Q000378:metabolism*; D016716:PC12 Cells; D011498:Protein Precursors / Q000235:genetics / Q000378:metabolism; D034622:RNA Interference; D051381:Rats; D014162:Transfection
chemical_list: D004745:Enkephalins; D009478:Neuropeptide Y; D018377:Neurotransmitter Agents; D011498:Protein Precursors; C029992:proenkephalin; D002403:Cathepsins; D003546:Cysteine Endopeptidases; C117627:CTSV protein, human