An essential role for Grk2 in Hedgehog signalling downstream of Smoothened
The G-protein-coupled receptor kinase 2 (adrbk2/GRK2) has been implicated in vertebrate Hedgehog (Hh) signalling based on the effects of its transient knock-down in mammalian cells and zebrafish embryos. Here, we show that the response to Hh signalling is effectively abolished in the absence of Grk2...
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sg-ntu-dr.10356-805212020-11-01T05:18:01Z An essential role for Grk2 in Hedgehog signalling downstream of Smoothened Zhao, Zhonghua Lee, Raymond Teck Ho Pusapati, Ganesh V. Iyu, Audrey Rohatgi, Rajat Ingham, Philip William Lee Kong Chian School of Medicine (LKCMedicine) Grk2 Hedgehog signalling phosphorylation PKA Smo The G-protein-coupled receptor kinase 2 (adrbk2/GRK2) has been implicated in vertebrate Hedgehog (Hh) signalling based on the effects of its transient knock-down in mammalian cells and zebrafish embryos. Here, we show that the response to Hh signalling is effectively abolished in the absence of Grk2 activity. Zebrafish embryos lacking all Grk2 activity are refractory to both Sonic hedgehog (Shh) and oncogenic Smoothened (Smo) activity, but remain responsive to inhibition of cAMP-dependent protein kinase (PKA) activity. Mutation of the kinase domain abrogates the rescuing activity of grk2 mRNA, suggesting that Grk2 acts in a kinase-dependent manner to regulate the response to Hh. Previous studies have suggested that Grk2 potentiates Smo activity by phosphorylating its C-terminal tail (CTT). In the zebrafish embryo, however, phosphomimetic Smo does not display constitutive activity, whereas phospho-null mutants retain activity, implying phosphorylation is neither sufficient nor necessary for Smo function. Since Grk2 rescuing activity requires the integrity of domains essential for its interaction with GPCRs, we speculate that Grk2 may regulate Hh pathway activity by downregulation of a GPCR. ASTAR (Agency for Sci., Tech. and Research, S’pore) Accepted version 2016-05-10T08:59:44Z 2019-12-06T13:51:22Z 2016-05-10T08:59:44Z 2019-12-06T13:51:22Z 2016 Journal Article Zhao, Z., Lee, R. T. H., Pusapati, G. V., Iyu, A., Rohatgi, R., & Ingham, P. W. (2016). An essential role for Grk2 in Hedgehog signalling downstream of Smoothened. EMBO reports, 17(5), 739-752. 1469-221X https://hdl.handle.net/10356/80521 http://hdl.handle.net/10220/40517 10.15252/embr.201541532 en EMBO reports © 2016 The Authors. Published under the terms of the CC BY NC ND 4.0 license. This is an open access article under the terms of the Creative Commons Attribution‐NonCommercial‐NoDerivs 4.0 License, which permits use and distribution in any medium, provided the original work is properly cited, the use is non‐commercial and no modifications or adaptations are made. 48 p. application/pdf |
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Grk2 Hedgehog signalling phosphorylation PKA Smo Zhao, Zhonghua Lee, Raymond Teck Ho Pusapati, Ganesh V. Iyu, Audrey Rohatgi, Rajat Ingham, Philip William An essential role for Grk2 in Hedgehog signalling downstream of Smoothened |
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The G-protein-coupled receptor kinase 2 (adrbk2/GRK2) has been implicated in vertebrate Hedgehog (Hh) signalling based on the effects of its transient knock-down in mammalian cells and zebrafish embryos. Here, we show that the response to Hh signalling is effectively abolished in the absence of Grk2 activity. Zebrafish embryos lacking all Grk2 activity are refractory to both Sonic hedgehog (Shh) and oncogenic Smoothened (Smo) activity, but remain responsive to inhibition of cAMP-dependent protein kinase (PKA) activity. Mutation of the kinase domain abrogates the rescuing activity of grk2 mRNA, suggesting that Grk2 acts in a kinase-dependent manner to regulate the response to Hh. Previous studies have suggested that Grk2 potentiates Smo activity by phosphorylating its C-terminal tail (CTT). In the zebrafish embryo, however, phosphomimetic Smo does not display constitutive activity, whereas phospho-null mutants retain activity, implying phosphorylation is neither sufficient nor necessary for Smo function. Since Grk2 rescuing activity requires the integrity of domains essential for its interaction with GPCRs, we speculate that Grk2 may regulate Hh pathway activity by downregulation of a GPCR. |
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Lee Kong Chian School of Medicine (LKCMedicine) |
author_facet |
Lee Kong Chian School of Medicine (LKCMedicine) Zhao, Zhonghua Lee, Raymond Teck Ho Pusapati, Ganesh V. Iyu, Audrey Rohatgi, Rajat Ingham, Philip William |
format |
Article |
author |
Zhao, Zhonghua Lee, Raymond Teck Ho Pusapati, Ganesh V. Iyu, Audrey Rohatgi, Rajat Ingham, Philip William |
author_sort |
Zhao, Zhonghua |
title |
An essential role for Grk2 in Hedgehog signalling downstream of Smoothened |
title_short |
An essential role for Grk2 in Hedgehog signalling downstream of Smoothened |
title_full |
An essential role for Grk2 in Hedgehog signalling downstream of Smoothened |
title_fullStr |
An essential role for Grk2 in Hedgehog signalling downstream of Smoothened |
title_full_unstemmed |
An essential role for Grk2 in Hedgehog signalling downstream of Smoothened |
title_sort |
essential role for grk2 in hedgehog signalling downstream of smoothened |
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2016 |
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https://hdl.handle.net/10356/80521 http://hdl.handle.net/10220/40517 |
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1683493507442933760 |