lysophosphatidic acid receptor activity

Definition

Target type: molecularfunction

Combining with the phospholipid derivative lysophosphatidic acid, and transmitting the signal across the membrane by activating an associated G-protein. [GOC:bf, GOC:mah, PMID:15755723]

Lysophosphatidic acid (LPA) receptor activity refers to the ability of a protein to bind and respond to LPA, a bioactive lipid that plays diverse roles in cell signaling. LPA receptors, also known as endothelial differentiation genes (EDG) receptors, are G protein-coupled receptors (GPCRs) that belong to the receptor family. These receptors are integral membrane proteins, meaning they span the cell membrane, with an extracellular domain that binds LPA and an intracellular domain that interacts with G proteins. Upon LPA binding, LPA receptors activate intracellular signaling pathways, leading to a variety of cellular responses.

Here's a breakdown of the molecular function of LPA receptor activity:

1. **LPA Binding:** LPA, a potent bioactive lipid, binds to the extracellular domain of the LPA receptor. This binding event initiates a conformational change in the receptor protein.

2. **G Protein Coupling:** The conformational change in the LPA receptor triggers the interaction with a G protein. G proteins are heterotrimeric proteins composed of alpha, beta, and gamma subunits. LPA receptors primarily couple with Gαi, Gαq, and Gα12/13 subtypes.

3. **Signal Transduction:** The activated G protein initiates downstream signaling pathways.
* **Gαi activation:** Inhibits adenylate cyclase, reducing the production of cyclic AMP (cAMP). This leads to decreased activity of protein kinase A (PKA) and modulation of various cellular processes.
* **Gαq activation:** Activates phospholipase C (PLC), which hydrolyzes phosphatidylinositol 4,5-bisphosphate (PIP2) into diacylglycerol (DAG) and inositol triphosphate (IP3). DAG activates protein kinase C (PKC), while IP3 increases intracellular calcium levels, influencing cell signaling and various cellular events.
* **Gα12/13 activation:** Activates Rho GTPases, which regulate cytoskeletal organization, cell migration, and proliferation.

4. **Cellular Responses:** The downstream signaling pathways activated by LPA receptors lead to a range of cellular responses, including:
* **Cell Proliferation and Growth:** LPA promotes cell division and growth in various cell types.
* **Cell Migration and Adhesion:** LPA influences cell movement and attachment to the extracellular matrix.
* **Survival and Apoptosis:** LPA can both promote cell survival and induce apoptosis, depending on the cellular context and signaling pathway activation.
* **Vascular Function:** LPA plays a role in regulating vascular tone, permeability, and angiogenesis.
* **Immune Responses:** LPA modulates immune cell function, influencing inflammation and immune responses.

5. **Tissue-Specific Functions:** LPA receptors are expressed in various tissues, including the nervous system, heart, lungs, liver, and immune system. Their activity contributes to diverse physiological and pathological processes in these tissues.

In summary, LPA receptor activity involves the binding of LPA, activation of G proteins, and subsequent modulation of intracellular signaling pathways. These events ultimately trigger a range of cellular responses crucial for various physiological processes and disease pathogenesis.
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Proteins (5)

Compounds (7)