G protein-coupled receptor homodimeric complex

Definition

Target type: cellularcomponent

A protein complex that contains two G protein-coupled receptors (GPCRs) of the same subtype. Formation of a GPCR homodimer may be important for the transport of newly formed receptors to the cell surface, and the function of the receptor. [GOC:al, GOC:bf, PMID:10713101, PMID:16670762]

G protein-coupled receptor (GPCR) homodimers are formed when two identical GPCR molecules associate with each other. This association can occur through various interactions, including transmembrane domain interactions, extracellular loop interactions, and interactions with intracellular signaling proteins. The cellular component of a GPCR homodimer is complex and dynamic, involving multiple cellular structures and processes.

**Plasma Membrane:**
- GPCR homodimers are primarily localized to the plasma membrane, where they are embedded within the lipid bilayer.
- The transmembrane domains of the GPCRs span the membrane, with their extracellular domains exposed to the external environment and their intracellular domains facing the cytoplasm.
- The plasma membrane provides a platform for the interaction of GPCR homodimers with extracellular ligands and intracellular signaling molecules.

**Lipid Rafts:**
- GPCR homodimers are often enriched in lipid rafts, which are specialized microdomains within the plasma membrane.
- Lipid rafts are characterized by their high cholesterol and sphingolipid content, creating a more ordered and rigid environment.
- The association of GPCR homodimers with lipid rafts facilitates their signaling and trafficking.

**Cytoskeleton:**
- The cytoskeleton, a network of protein filaments that provides structural support to cells, plays a role in the localization and signaling of GPCR homodimers.
- GPCR homodimers can interact with cytoskeletal proteins, such as actin and tubulin, which can influence their trafficking and signaling.

**Signal Transduction Complexes:**
- GPCR homodimers often associate with other proteins to form signal transduction complexes.
- These complexes may include G proteins, adaptor proteins, kinases, and phosphatases.
- The formation of these complexes enables the efficient propagation of signals downstream of GPCR activation.

**Intracellular Compartments:**
- In addition to the plasma membrane, GPCR homodimers can also be found in intracellular compartments, such as the endoplasmic reticulum (ER) and Golgi apparatus.
- The ER serves as the site of GPCR synthesis and folding, while the Golgi apparatus is involved in protein sorting and trafficking.
- The trafficking of GPCR homodimers between these compartments can be regulated by various mechanisms.

**Dynamic Nature:**
- The cellular component of a GPCR homodimer is not static but rather dynamic.
- GPCR homodimers can undergo conformational changes upon ligand binding, which can alter their interactions with other cellular components.
- The localization and signaling of GPCR homodimers can be regulated by various cellular processes, including phosphorylation, ubiquitination, and endocytosis.

In summary, the cellular component of a GPCR homodimer is a complex and dynamic entity that involves multiple cellular structures, processes, and interactions. The localization and signaling of GPCR homodimers are regulated by various factors, including lipid rafts, the cytoskeleton, signal transduction complexes, and intracellular trafficking.'
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Proteins (1)

Compounds (49)