Table 1.
Posttranslational modifications with cellular function in mammal MCHR1.
| Region | Mutant receptor | Impact on MCHR1 in HEK293 cells | Reference | |
|---|---|---|---|---|
| Extracellular N-terminus | N23Qa | |||
| N13Q/N16Qa | ⇓ Mature glycosylation | |||
| N13Q/N23Qa | ⇓ Cell surface expression | (51, 52) | ||
| N16Q/N23Qa | ⇓ Ca2+ mobilization | |||
| N13Q/N16Q/N23Qa | ||||
| Intracellular loop 2 | D140A | ⇓ Mature glycosylation | (53) | |
| Y142A | ⇓ Cell surface expression | |||
| Loss of function (Ca2+ mobilization, cAMP inhibition, ERK activation) | ||||
| Transmembrane region | 2 | P97A | ||
| 4 | P177A | |||
| ⇓ Mature glycosylation | ||||
| 5 | P220A | |||
| 6 | P271A | |||
| Loss of function (Ca2+ mobilization) | ||||
| 7 | P308A | (50) | ||
| Junction of intracellular loop 3 and transmembrane region 6 | T255Ab | ⇓ Mature glycosylation | (52) | |
| ⇓ Cell surface expression (retained in the ER) | ||||
| Loss of function (Ca2+ mobilization) | ||||
| Intracellular C-terminus | T317A/S325A/T342Ab | → Ca2+ mobilization | (55) | |
| ⇓ Receptor internalization (protein kinase C and β-arrestin 2-dependent) | ||||
aThe consensus sequences for N-linked glycosylation.
bPredicted phosphorylation sites.