G protein-coupled receptors (GPCRs), also known as seven-(pass)-transmembrane domain receptors, 7TM receptors, heptahelical receptors, serpentine receptors, and G protein-linked receptors (GPLR), form a large group of evolutionarily related proteins that are cell surface receptors that detect molecules outside the cell and activate cellular responses. They are coupled with G proteins. They pass through the cell membrane seven times in the form of six loops of amino acid residues, which is why they are sometimes referred to as seven-transmembrane receptors. Ligands can bind either to the extracellular N-terminus and loops or to the binding site within transmembrane helices. They are all activated by agonists, although a spontaneous auto-activation of an empty receptor has also been observed.
Receptor-mediated endocytosis (RME), also called clathrin-mediated endocytosis, is a process by which cells absorb metabolites, hormones, proteins – and in some cases viruses – by the inward budding of the plasma membrane (invagination). This process forms vesicles containing the absorbed substances and is strictly mediated by receptors on the surface of the cell. Only the receptor-specific substances can enter the cell through this process.
The actions of vasopressin are mediated by stimulation of tissue-specific G protein-coupled receptors (GPCRs) called vasopressin receptors that are classified into the V1 (V1A), V2, and V3 (V1B) receptor subtypes. These three subtypes differ in localization, function and signal transduction mechanisms.
Arrestins are a small family of proteins important for regulating signal transduction at G protein-coupled receptors. Arrestins were first discovered as a part of a conserved two-step mechanism for regulating the activity of G protein-coupled receptors (GPCRs) in the visual rhodopsin system by Hermann Kühn, Scott Hall, and Ursula Wilden and in the β-adrenergic system by Martin J. Lohse and co-workers.
G protein-coupled receptor kinases are a family of protein kinases within the AGC group of kinases. Like all AGC kinases, GRKs use ATP to add phosphate to Serine and Threonine residues in specific locations of target proteins. In particular, GRKs phosphorylate intracellular domains of G protein-coupled receptors (GPCRs). GRKs function in tandem with arrestin proteins to regulate the sensitivity of GPCRs for stimulating downstream heterotrimeric G protein and G protein-independent signaling pathways.
G-protein-coupled receptor kinase 2 (GRK2) is an enzyme that in humans is encoded by the ADRBK1 gene. GRK2 was initially called Beta-adrenergic receptor kinase, and is a member of the G protein-coupled receptor kinase subfamily of the Ser/Thr protein kinases that is most highly similar to GRK3(βARK2).
Rhodopsin kinase is a serine/threonine-specific protein kinase involved in phototransduction. This enzyme catalyses the following chemical reaction:
Robert Joseph Lefkowitz is an American physician and biochemist. He is best known for his discoveries that reveal the inner workings of an important family G protein-coupled receptors, for which he was awarded the 2012 Nobel Prize for Chemistry with Brian Kobilka. He is currently an Investigator with the Howard Hughes Medical Institute as well as a James B. Duke Professor of Medicine and Professor of Biochemistry and Chemistry at Duke University.
Atypical chemokine receptor 3 also known as C-X-C chemokine receptor type 7 (CXCR-7) and G-protein coupled receptor 159 (GPR159) is a protein that in humans is encoded by the ACKR3 gene.
Arrestin, beta 1, also known as ARRB1, is a protein which in humans is encoded by the ARRB1 gene.
Brian Kent Kobilka is an American physiologist and a recipient of the 2012 Nobel Prize in Chemistry with Robert Lefkowitz for discoveries that reveal the workings of G protein-coupled receptors. He is currently a professor in the department of Molecular and Cellular Physiology at Stanford University School of Medicine. He is also a co-founder of ConfometRx, a biotechnology company focusing on G protein-coupled receptors. He was named a member of the National Academy of Sciences in 2011.
Trevena Inc is a clinical stage biopharmaceutical company, headquartered in Chesterbrook, Pennsylvania, USA, and is involved in the discovery and development of G-protein coupled receptors (GPCR) biased ligands. Trevena was founded in 2007 with technology licensed from Duke University, which originated in the labs of company founders Robert Lefkowitz winner of the 2012 Nobel Prize in Chemistry and Howard Rockman. Trevena's approach to drug discovery is based on utilizing ligand bias, or functional selectivity, at GPCR targets to produce drugs with improved efficacy and reduced side effect profiles. Trevena was named one of the top 15 US startups of 2008 by Business Week.
Martin J. Lohse is a German physician and pharmacologist.
G-protein-coupled receptor kinase 3 (GRK3) is an enzyme that in humans is encoded by the ADRBK2 gene. GRK3 was initially called Beta-adrenergic receptor kinase 2 (βARK-2), and is a member of the G protein-coupled receptor kinase subfamily of the Ser/Thr protein kinases that is most highly similar to GRK2.
Sandeep Verma is an Indian bioorganic chemist and chemical biologist, and a Professor in the Department of Chemistry at the Indian Institute of Technology, Kanpur (IITK). At IITK, he heads Sandeep Verma's Research Group in the areas of ordered peptide assemblies, metal-mediated nanoscale systems, programmable soft matter for neuronal regeneration, novel antimicrobials, and small molecule-stem cell modulation. He is an elected fellow of the Indian National Science Academy (INSA), the Indian Academy of Sciences, the National Academy of Sciences, India, and the Indian National Academy of Engineering. The Council of Scientific and Industrial Research, the apex agency of the Government of India for scientific research, awarded him the Shanti Swarup Bhatnagar Prize for Science and Technology, one of the highest Indian science awards, in 2010, for his contributions to Chemical Sciences.
Ramasubbu Sankararamakrishnan is an Indian computational biologist, bioinformatician and a professor at the Department of Biological Sciences and Bioengineering of the Indian Institute of Technology, Kanpur. He is known for his computational studies on membrane protein function. The Department of Biotechnology of the Government of India awarded him the National Bioscience Award for Career Development, one of the highest Indian science awards, for his contributions to biosciences in 2008.
Subramaniam Ganesh is an Indian geneticist, molecular biologist and a professor at the department of biological sciences and bio-engineering of the Indian Institute of Technology, Kanpur. Known for his pioneering studies on Lafora progressive myoclonic epilepsy and other neurodegenerative disorders, Ganesh is an elected fellow of the Indian Academy of Sciences and the National Academy of Sciences, India. The Department of Biotechnology of the Government of India awarded him the National Bioscience Award for Career Development, one of the highest Indian science awards, for his contributions to biosciences in 2008.
Sadashiva "Sadu" Karnik is an Indian-born American molecular biologist who is a Professor in the Molecular Medicine Department of Cleveland Clinic Lerner College of Medicine at Case Western Reserve University. He is the Principal Investigator of the Sadashiva Karnik Laboratory, at the Lerner Research Institute of Cleveland Clinic.
Raul Gainetdinov is a pharmacologist and neuroscientist. The main direction of his research is psychiatric and neurological diseases of the brain, such as schizophrenia, ADHD, depression and Parkinson's disease. He is the author of fundamental scientific works in pharmacology of dopamine, β-Arrestins and NMDA receptors. He is a pioneer researcher of Trace amine-associated receptors.
