Isopeptide and ester bond ubiquitination both regulate degradation of the human dopamine receptor 4.
J Biol Chem
; 292(52): 21623-21630, 2017 12 29.
Article
em En
| MEDLINE
| ID: mdl-29101232
ABSTRACT
How an optimal level of human dopamine D4 receptor (hD4R) is maintained in synaptic membranes is not known. We show here that hD4R is ubiquitinated in primary neurons. We go on to show that ubiquitin is attached to hD4R through isopeptide and ester bonds. When lysine (Lys) residues of the hD4R are substituted with arginine (Arg) residues, cellular hD4R protein levels increase. A synergistic effect on hD4R levels is noted when cytoplasmic serine (Ser) and threonine (Thr) residues are mutated. Chloroquine, an inhibitor of lysosomal degradation, did not have an effect on hD4R protein levels. However, treatment with bortezomib, an inhibitor of the 20S proteasome, caused a dose-dependent increase in hD4R protein levels. The effect of bortezomib was attenuated in the receptor variants that lacked Lys or Ser/Thr residues, and the hD4R mutant that lacked 17 cytoplasmic Lys, Ser, and Thr residues was nearly insensitive to bortezomib treatment. We conclude that both isopeptide and ester bond ubiquitination regulate proteasomal degradation of hD4R.
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Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Receptores de Dopamina D4
Limite:
Humans
Idioma:
En
Revista:
J Biol Chem
Ano de publicação:
2017
Tipo de documento:
Article