Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
8477025 | Molecular and Cellular Endocrinology | 2015 | 11 Pages |
Abstract
The type II GnRH receptor (GnRH-R2) in contrast to mammalian type I GnRH receptor (GnRH-R1) has a cytosolic carboxy-terminal tail. We investigated the role of β-arrestin 1 in GnRH-R2-mediated signalling and mapped the regions in GnRH-R2 required for recruitment of β-arrestin, employing internalization assays. We show that GnRH-R2 activation of ERK is dependent on β-arrestin and protein kinase C. Appending the tail of GnRH-R2 to GnRH-R1 enabled GRK- and β-arrestin-dependent internalization of the chimaeric receptor. Surprisingly, carboxy-terminally truncated GnRH-R2 retained β-arrestin and GRK-dependent internalization, suggesting that β-arrestin interacts with additional elements of GnRH-R2. Mutating serine and threonine or basic residues of intracellular loop 3 did not abolish β-arrestin 1-dependent internalization but a receptor lacking these basic residues and the carboxy-terminus showed no β-arrestin 1-dependent internalization. Our results suggest that basic residues at the amino-terminal end of intracellular loop 3 or the carboxy-terminal tail are required for β-arrestin dependent internalization.
Keywords
PKCIC3β-arrestinIC2intracellular loop 3GRKGPCREC50DMEMERKSDSIC50Dulbecco's modified Eagle MediumG protein-coupled receptor kinaseInternalizationsodium dodecyl sulphateinositol phosphatestransmembrane helixhalf-maximal inhibitory concentrationfollicle-stimulating hormoneluteinising hormoneFSHProtein kinase Cextracellular signal-regulated kinasesGnRH receptorG protein-coupled receptor
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Authors
Michael T. Madziva, Nonhlanhla N. Mkhize, Colleen A. Flanagan, Arieh A. Katz,