Is GPR55 an orphan receptor?

In this study we show that the orphan G-protein-coupled receptor, GPR55, is a novel cannabinoid receptor with an ability to interact with and be modulated by endogenous, plant and synthetic cannabinoid ligands and to be a candidate for one of the non-CB1/CB2 receptors, described by others.

What is GPR55?

The G protein-coupled receptor 55 (GPR55) is a novel cannabinoid receptor, whose exact role in anxiety remains unknown. The present study was conducted to explore the possible mechanisms by which GPR55 regulates anxiety and to evaluate the effectiveness of O-1602 in the treatment of anxiety-like symptoms.

Where are GPR55 receptors located?

GPR55 is widely expressed in the brain, especially in the cerebellum. It is expressed in the jejunum and ileum but apparently not more generally in the periphery. Osteoblasts and osteoclasts express GPR55 and this has been shown to regulate bone cell function.

What do cannabinoid receptors do?

Cannabinoid receptors, located throughout the body, are part of the endocannabinoid system, which is involved in a variety of physiological processes including appetite, pain-sensation, mood, and memory. Cannabinoid receptors are of a class of cell membrane receptors in the G protein-coupled receptor superfamily.

What do you mean by orphan receptor?

Definition. Orphan receptors are proteins that bind and are activated by hitherto unknown signaling molecules (called ligands, neurotransmitters, or hormones). However, they share structural components with identified receptors whose signaling molecules are already known.

What is AG protein?

G proteins, also known as guanine nucleotide-binding proteins, are a family of proteins that act as molecular switches inside cells, and are involved in transmitting signals from a variety of stimuli outside a cell to its interior. G proteins belong to the larger group of enzymes called GTPases.

Is there a CB3 receptor?

Cannabinoid receptors are G protein-coupled receptors with seven transmembrane domains that are expressed on the cell surface with their binding domain exposed to the extracellular space. Recent evidence suggests that a third CB3 receptor is out there, waiting to be cloned.

Do cannabinoids relieve pain?

1). Cannabinoid receptor agonists modulate nociceptive thresholds by regulating neuronal activity [4], but they also relieve pain by acting on non-nervous tissues.

What family do cannabinoid receptors belong to?

The cannabinoid CB1 receptor (see Fig. 1) belongs to the Class A (rhodopsin (Rho) family) of G-protein coupled receptors (GPCRs).

Where do orphan genes come from?

An orphan gene can form through the rapid divergence of the coding sequence (CDS) of an existing gene (1), or arise de novo from regions of the genome that do not code for proteins (including the non-coding parts of genes that evolve to code for proteins; 2).

What does Orphan mean in biology?

Orphan genes (also called ORFans, especially in microbial literature) are genes without detectable homologues in other lineages. Orphans are a subset of taxonomically-restricted genes (TRGs), which are unique to a specific taxonomic level (e.g. plant-specific).

What happens when ag protein is activated?

When a ligand activates the G protein-coupled receptor, it induces a conformational change in the receptor that allows the receptor to function as a guanine nucleotide exchange factor (GEF) that exchanges GDP for GTP.