GRK3
GRK3 (G protein-coupled receptor kinase 3, also known as BARK2 and ADRBK2) is a serine/threonine kinase that phosphorylates agonist-activated G protein-coupled receptors. This phosphorylation starts the process of receptor desensitisation. Browse Assay Genie's current range of GRK3 research reagents below, or read on for the biology behind the target.
GRK3 specifically phosphorylates the activated forms of G protein-coupled receptors. Receptor phosphorylation initiates beta-arrestin-mediated receptor internalisation and signalling events that lead to desensitisation. GRK3 acts on the agonist-occupied form of the beta-adrenergic receptor and closely related receptors. It also phosphorylates ligand-bound C3a and C5a anaphylatoxin receptors (C3AR1 and C5AR1), which leads to their desensitisation.
GRK3 also positively regulates the ciliary smoothened (SMO) signalling pathway. It phosphorylates SMO, which facilitates SMO trafficking into the cilium and stimulates SMO activity. UniProt lists its subcellular locations as the postsynapse and the presynapse. The protein belongs to the protein kinase superfamily, in the AGC Ser/Thr protein kinase family and the GPRK subfamily. HGNC places the GRK3 gene in the G protein-coupled receptor kinase family and among pleckstrin homology domain containing proteins. Mouse and rat both have a Grk3 ortholog.
The older names reflect the original description of the enzyme as a beta-adrenergic receptor kinase: BARK2, ADRBK2 and "adrenergic, beta, receptor kinase 2". According to the NCBI Gene summary, beta adrenergic receptor kinase 2 shares 85% amino acid similarity with beta adrenergic receptor kinase 1, and 95% similarity in the protein kinase catalytic domain. This suggests a family of receptor kinases that may serve broadly to regulate receptor function.
GRK3 phosphorylates agonist-occupied receptors, initiating beta-arrestin-mediated internalisation and desensitisation, so it is a focus for studies of receptor signalling control.
GRK3 phosphorylates the agonist-occupied beta-adrenergic receptor and closely related receptors, which makes it relevant to adrenergic receptor regulation.
GRK3 phosphorylates ligand-bound C3a and C5a anaphylatoxin receptors, leading to desensitisation, which links it to anaphylatoxin receptor signalling.
GRK3 phosphorylates SMO, facilitating its trafficking into the cilium and stimulating its activity in the ciliary smoothened signalling pathway.
GRK3 specifically phosphorylates the activated forms of G protein-coupled receptors, which initiates beta-arrestin-mediated internalisation and desensitisation. It also phosphorylates SMO, facilitating SMO trafficking into the cilium and stimulating its activity in the ciliary smoothened signalling pathway.
GRK3 was previously called beta-adrenergic receptor kinase 2, with the symbols BARK2 and ADRBK2. HGNC lists the older name as "adrenergic, beta, receptor kinase 2". These names reflect its activity towards the agonist-occupied beta-adrenergic receptor.
Mouse and rat each have a Grk3 ortholog. GRK3 belongs to the AGC Ser/Thr protein kinase family, GPRK subfamily. NCBI reports 85% amino acid similarity to beta adrenergic receptor kinase 1, rising to 95% in the catalytic domain. Check the datasheet of any product for its validated reactivity.
Other members of the G protein-coupled receptor kinase family with products at Assay Genie.
Gene and protein annotations from HGNC, NCBI Gene and UniProt P35626; product specifications from Assay Genie datasheets.