G protein-coupled receptor kinases (GRKs) are serine/threonine protein kinases best known for their ability to phosphorylate activated G protein-coupled receptors. Numerous studies have revealed that GRKs are important regulators of normal cell and organism function and contribute to a number of human diseases including cardiovascular disease, cancer and neurological disorders. While there has been significant progress in understanding GRK function, the mechanistic basis for many of the in vivo functions of GRKs remains largely unknown. During the last grant period, we initiated studies on the two C. elegans GRKs and found that they regulate a number of important biological processes including egg-laying, growth and sex determination. Interestingly, our work revealed that GRK-2 regulates serotonin metabolism and that GRK-1 and GRK-2 mediate opposing effects on egg-laying. Moreover, the serotonin metabolite 5-HIAA was found to bind to SER-1, a 5-HT2A receptor ortholog, and oppose the effects of serotonin. To further define the biological role of GRKs and provide mechanistic insight into how GRK structure correlates with in vivo function, we propose to use molecular, biochemical and cell biological strategies to better define the mechanistic basis for GRK regulation of egg-laying. Our central hypothesis is that these studies will enable us to mechanistically link GRK structure/function with important biological processes in the worm and that our findings will provide novel insight relevant to understanding the physiological and pathophysiological role of GRKs in humans. We plan to test our central hypothesis by pursuing three specific aims.
In aim 1, we will elucidate the mechanisms involved in GRK-2 regulation of egg-laying and test the hypotheses that: (A) GRK-2 regulates serotonin metabolism by regulating vesicular monoamine transporter and/or monoamine oxidase activity and (B) 5-HIAA functions as a biased SER-1 agonist.
In aim 2, we will elucidate the mechanisms involved in GRK-1 regulation of egg-laying and test the hypothesis that GRK-1 stimulates Go signaling.
In aim 3, we will use molecular and proteomic strategies to define the in vivo interactions and substrates for C. elegans GRKs. We are poised to mechanistically dissect how GRK-2 regulates serotonin metabolism, how serotonin and 5-HIAA differentially modulate serotonin receptor function and how GRK-1 and GRK-2 coordinately regulate biology. These studies will provide important insight that is highly relevant to not only understanding GRKs in the worm but also to understanding how GRKs function in humans.
GRKs are important regulators of normal organism function and contribute to a number of human diseases including cardiovascular disease, cancer and various neurological disorders. The proposed research is relevant to public health and the NIH mission because it will elucidate the mechanisms involved in GRK function in vivo and thereby provide important insight into the pathophysiological role of GRKs in humans.
|Komolov, Konstantin E; Bhardwaj, Anshul; Benovic, Jeffrey L (2015) Atomic Structure of GRK5 Reveals Distinct Structural Features Novel for G Protein-coupled Receptor Kinases. J Biol Chem 290:20629-47|
|Kang, Dong Soo; Tian, Xufan; Benovic, Jeffrey L (2014) Role of Î²-arrestins and arrestin domain-containing proteins in G protein-coupled receptor trafficking. Curr Opin Cell Biol 27:63-71|
|Carr 3rd, Richard; Du, Yang; Quoyer, Julie et al. (2014) Development and characterization of pepducins as Gs-biased allosteric agonists. J Biol Chem 289:35668-84|
|Quoyer, Julie; Janz, Jay M; Luo, Jiansong et al. (2013) Pepducin targeting the C-X-C chemokine receptor type 4 acts as a biased agonist favoring activation of the inhibitory G protein. Proc Natl Acad Sci U S A 110:E5088-97|
|Kang, Dong Soo; Tian, Xufan; Benovic, Jeffrey L (2013) Î²-Arrestins and G protein-coupled receptor trafficking. Methods Enzymol 521:91-108|
|So, Christopher H; Michal, Allison; Komolov, Konstantin E et al. (2013) G protein-coupled receptor kinase 2 (GRK2) is localized to centrosomes and mediates epidermal growth factor-promoted centrosomal separation. Mol Biol Cell 24:2795-806|
|Woerner, B Mark; Luo, Jingqin; Brown, Kristin R et al. (2012) Suppression of G-protein-coupled receptor kinase 3 expression is a feature of classical GBM that is required for maximal growth. Mol Cancer Res 10:156-66|
|Li, Guo; Zhou, Qi; Yu, Yena et al. (2012) Identification and characterization of distinct C-terminal domains of the human hydroxycarboxylic acid receptor-2 that are essential for receptor export, constitutive activity, desensitization, and internalization. Mol Pharmacol 82:1150-61|
|Wood, Jordan F; Wang, Jianjun; Benovic, Jeffrey L et al. (2012) Structural domains required for Caenorhabditis elegans G protein-coupled receptor kinase 2 (GRK-2) function in vivo. J Biol Chem 287:12634-44|
|Michal, Allison M; So, Christopher H; Beeharry, Neil et al. (2012) G Protein-coupled receptor kinase 5 is localized to centrosomes and regulates cell cycle progression. J Biol Chem 287:6928-40|
Showing the most recent 10 out of 119 publications