Basic Information

Symbol
OPRPN
RNA class
mRNA
Alias
Opiorphin Prepropeptide BPLP PRL1 PROL1 Basic Proline-Rich Lacrimal Protein Proline Rich, Lacrimal 1 Proline-Rich Protein 1 Basic Proline-Rich Protein Proline Rich 1 Proline-Rich 1 Opiorphin
Location (GRCh38)
4:70397931-70410195
UCSC Genome Browser Search in Marker Scope
Forensic tag(s)
Tissue/body fluid identification
External database
HGNC NCBI Ensembl OMIM UniProt GTEx

MANE select

Transcript ID
NM_021225.5
Sequence length
983.0 nt
GC content
0.4232

Secondary Structure

Generated by RNAfold
Minimum free energy (MFE) structure:
Secondary structure that contributes a minimum of free energy.
Ensemble properties:
Thermodynamic properties of the Boltzmann ensemble.
Minimum free energy
-163.40 kcal/mol
Thermodynamic ensemble
Free energy: -181.11 kcal/mol
Frequency: 0.0000
Diversity: 208.57
MFE Structure Visualization
Structure Prediction
MFE Structure Prediction
.......(((....(((((......((((((...........(((..(((((((((.((((............(((((((..(((((...))))).....))))))).....(((((.((((.....))))))))).((((((((((((((((((...(((...)))...))))))))))).(((((((.....)))....))))...((((.....)))).............)))))))..(((((((((((..(((..............((((((..........................((((.......))))((((..................)))).....((...))))))))............))).....))))))))))).((.((((.((........)))))).))....(((((((...................)))))))......(((((...................)))))....)))).)))))))))..)))........(((.......))).....................((((..............................))))....((........)).......................((((((.(((((((((((...(((.(((((.......(((........))).(((((((.((((.......(((......)))..........................(((.((...(((((...((.....)).)))))...))..))).....((((((((.........((......)).............(((((((.....)))))))..))))))))..(((.......))).............)))))))))))....))))).))).))))........)))).))).......)))))).....))).))).....)))))....)))......
Thermodynamic Ensemble Prediction
.....,,.,,..,,(((({....,,((((({.......,,{.(((,,(((((((((.((({..,,,.,,,,..{((((((..(((((...))))).....))))))).....(((((.((({.....})))))))).((((((((((((((((((...(((...)))...))))))))))).{{{{,,,...,.}}}....})))...{(((.....)))}.............})))))).,((((((({({{..,{{,,........,,,,..{{(,.,,{,,,................,..,{|{..},,..)))){|{|..................}}}),....{,...},||}},,..............,.....})))))}}}}}.((.((((.{(........}))))).))....(((((((...................)))))))......,((((................,,,),})}....}}}}.}))))))}}..}},........(((.......))).....................,|||}},,....,,....................,|||....||,.......},...................,,..((((((.{{{((({((((...(((.(((((.....((((((..,........((((((({,((.......}|,|}.....,||{.........................,({.,,...(((((...((.....)).)))))...|},.,,)}}...{{({((({,,.....,,((......)),.,.,,.}},...(((((((.....)))))))..,}))))))....},,......))}))}..........))))))......,.))))).))).))))........)))}.))).......)))))).....})}.}}}.....}))))....)))......

Transcripts

ID Sequence Length GC content
NM_001302807.2 NCBI
CUUUCUCUUCUUGGACUUUUAAAUUGUGGCUACCUAAAUUGAGUAUCUG… 1039 nt 0.4312
NM_021225.5 NCBI
CUUUCUCUUCUUGGACUUUUAAAUUGUGGCUACCUAAAUUGAGUAUCUG… 983 nt 0.4232
Summary

This gene encodes a member of the proline-rich protein family. The encoded protein has multiple proposed functions, including roles in pain suppression, penile erection, and protection of the eye surface. The QRFSR pentapeptide, known as opiorphin, is derived from the N-terminal of this protein. Opiorphin inhibits the enkephalin-inactivating peptidases neprilysin and aminopeptidase N, and this activity is thought to reduce sensitivity to painful stimuli by effecting enkephalin-related activation of opioid-dependent pathways. Opiorphin may also act as an anti-depressant. Alternative splicing results in multiple transcript variants. [provided by RefSeq, Nov 2014]

Forensic Context

A study in humans identified the OPRPN as a candidate mRNA marker for nasal mucosa detection via RNA sequencing [Chirnside et al. DOI:10.1016/j.fsigen.2020.102317]. Initial testing showed the marker could amplify in nasal samples, though it exhibited potential for dropout and was undetected in samples from donors with allergies or unknown causes, while being detected in samples from illness or after eating spicy food. Specificity testing at a 0.01 μM primer concentration revealed no cross-reactions in non-nasal body fluids, and the primer set did not amplify genomic DNA, leading to its proposal as a final candidate marker for forensic assays to identify nasal mucosa and interpret potential false positives.