Proenkephalin

Proenkephalin (PENK), formerly known as proenkephalin A (since proenkephalin B was renamed prodynorphin), is an endogenous opioid polypeptide hormone which, via proteolyic cleavage, produces the enkephalin peptides met-enkephalin, and to a lesser extent, leu-enkephalin.^[5] Upon cleavage, each proenkephalin peptide results in the generation of four copies of Met-enkephalin, two extended copies of met-enkephalin, and one copy of leu-enkephalin.^[5] Contrarily, Leu-enkephalin is predominantly synthesized from prodynorphin, which produces three copies of it per cleavage, and no copies of Met-enkephalin. Other endogenous opioid peptides produced by proenkephalin include adrenorphin,^[6] amidorphin,^[7] BAM-18,^[8] BAM-20P,^[9] BAM-22P,^[9] peptide B,^[10] peptide E,^[11] and peptide F.^[12]

PENK
Available structures PDB Ortholog search: PDBe RCSB List of PDB id codes 1PLW, 1PLX, 2LWC, 5E33, 5E3A
Identifiers
Aliases	PENK, proenkephalin, PE, PENK-A
External IDs	OMIM: 131330; MGI: 104629; HomoloGene: 4528; GeneCards: PENK; OMA:PENK - orthologs
Gene location (Human) Chr. Chromosome 8 (human)[1] Band 8q12.1 Start 56,436,674 bp[1] End 56,446,671 bp[1]
Gene location (Mouse) Chr. Chromosome 4 (mouse)[2] Band 4 A1|4 2.31 cM Start 4,133,531 bp[2] End 4,138,819 bp[2]
RNA expression pattern Bgee Human Mouse (ortholog) Top expressed in nucleus accumbens putamen right testis left testis cartilage tissue caudate nucleus ganglionic eminence middle frontal gyrus external globus pallidus urethra Top expressed in ciliary body olfactory tubercle nucleus accumbens globus pallidus superior frontal gyrus efferent ductule entorhinal cortex calvaria skin of external ear iris More reference expression data BioGPS n/a
Gene ontology Molecular function opioid peptide activity protein binding neuropeptide hormone activity opioid receptor binding Cellular component perikaryon cell body fiber axon symmetric synapse dendrite plasma membrane axon terminus soma extracellular region endoplasmic reticulum lumen synaptic vesicle lumen neuronal dense core vesicle lumen Biological process cellular response to transforming growth factor beta stimulus cellular response to virus general adaptation syndrome, behavioral process response to estradiol response to hypoxia startle response locomotory behavior response to nicotine ageing response to epinephrine cellular response to vitamin D behavioral fear response locomotory exploration behavior response to calcium ion response to morphine response to lipopolysaccharide osteoblast differentiation glial cell proliferation sensory perception of pain cellular response to oxidative stress response to radiation response to ethanol positive regulation of behavioral fear response response to toxic substance cellular response to cAMP aggressive behavior signal transduction sensory perception neuropeptide signaling pathway chemical synaptic transmission post-translational protein modification regulation of signaling receptor activity G protein-coupled receptor signaling pathway response to bacterium Sources:Amigo / QuickGO
Orthologs Species Human Mouse Entrez 5179 18619 Ensembl ENSG00000181195 ENSMUSG00000045573 UniProt P01210 P22005 RefSeq (mRNA) NM_006211 NM_001135690 NM_001002927 NM_001348209 RefSeq (protein) NP_001129162 NP_001002927 NP_001335138 Location (UCSC) Chr 8: 56.44 – 56.45 Mb Chr 4: 4.13 – 4.14 Mb PubMed search [3] [4]
Wikidata
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Clinical significance

Proenkephalin is produced by the medium spiny neurons of the striatum which undergo neurodegeneration in early stages of Huntington's disease (HD). PENK^[13] and related peptides^[14][15] measured in cerebrospinal fluid are proposed as potential biomarkers of disease progression in HD. Furthermore, PENK has been found associated with acute kidney injury^[16] and glomerular filtration rate in steady-state and critically ill patients.^[17][18]

See also

• Prodynorphin (Proenkephalin B)
• Proopiomelanocortin (POMC)