Olfactory marker protein is unlikely to be cleaved by calpain 5.
Mol Brain
; 15(1): 87, 2022 10 29.
Article
in En
| MEDLINE
| ID: mdl-36309704
ABSTRACT
Olfactory maturation marker protein (OMP) is expressed in olfactory receptor neurons and hypothalamic neurons. OMP is a nested gene located in the intron of calpain 5 (CAPN5), a Ca2+-dependent cysteine protease. Despite being located at the same genomic locus, genetic regulation of the reciprocal expression of OMP and CAPN5 has been suggested. By performing a motif search, we detected possible calpain cleavage sites in OMP. However, the direct proteolytic regulation of OMP by CAPN5 is unclear. Here, we generated OMP fused with Myc-tag and His-tag at its N- and C-termini and examined whether CAPN5 cleaves OMP into fragments by detecting immunoreactivity against Myc, OMP and His. Western blotting demonstrated that OMP was unlikely to be cleaved even in the presence of Ca2+ in vitro. We expressed OMP and CAPN5 in HEK293T cells and applied a calcium ionophore under physiological conditions in cellulo, which resulted in no apparent fragmentation of OMP. We also applied liquid chromatography/mass spectrometry to the electrophoresed fractions smaller than the uncut Myc-OMP-His signals, which demonstrated no significant fragmentation of OMP. These results collectively indicate that OMP is unlikely to be cleaved by CAPN5.
Key words
Full text:
1
Collection:
01-internacional
Database:
MEDLINE
Main subject:
Calpain
/
Olfactory Receptor Neurons
Limits:
Humans
Language:
En
Journal:
Mol Brain
Journal subject:
BIOLOGIA MOLECULAR
/
CEREBRO
Year:
2022
Document type:
Article
Affiliation country:
Japón