What is the Difference Between G Protein Linked Receptors and Enzyme Linked Receptors?
🆚 Go to Comparative Table 🆚G protein-linked receptors and enzyme-linked receptors are two types of transmembrane proteins that play crucial roles in cell signaling. The main differences between them are:
- Activation mechanism: G protein-linked receptors activate G proteins upon binding with an extracellular ligand, while enzyme-linked receptors bind with extracellular ligands and activate enzymes that trigger a chain reaction within the cell.
- Structure: G protein-linked receptors have seven transmembrane segments, whereas enzyme-linked receptors usually have only one transmembrane segment.
- Intracellular domain: G protein-linked receptors have a cytosolic domain that associates with a trimeric G protein, while the intracellular domain of enzyme-linked receptors either has intrinsic enzyme activity or associates directly with an enzyme.
- Signal transduction: In G protein-linked receptors, the activated G-protein interacts with either an ion channel or an enzyme in the membrane, leading to a cellular response. In contrast, enzyme-linked receptors directly activate enzymes, which then initiate a signaling cascade within the cell.
In summary, G protein-linked receptors activate G proteins upon ligand binding, while enzyme-linked receptors directly activate enzymes. Both types of receptors play essential roles in cell signaling and regulating various cellular functions.
Comparative Table: G Protein Linked Receptors vs Enzyme Linked Receptors
Here is a table comparing G protein-linked receptors and enzyme-linked receptors:
| Feature | G Protein-Linked Receptors | Enzyme-Linked Receptors |
|---|---|---|
| Definition | Cell surface receptors that activate G proteins upon binding with an extracellular ligand. | Receptors with ligand-binding domain on the outer surface and a cytosolic domain that either has intrinsic enzyme activity or associates directly with an enzyme. |
| Transmembrane Segments | Seven transmembrane segments. | Usually one transmembrane segment. |
| Activation | Activate trimeric G proteins. | Activate directly or indirectly enzymes. |
| Signal Transduction | Indirectly activate or inactivate plasma-membrane-bound enzymes or ion channels via G proteins. | Directly trigger a chain reaction of enzymatic reactions, leading to a cellular response. |
| Examples | GPCRs, which mediate responses to a wide variety of signal molecules. | Receptor tyrosine kinases, receptor serine-threonine kinases, receptor guanylyl cyclases, and histidine-kinase-associated receptors. |
G protein-linked receptors work with G proteins that associate with GTP, and when a ligand binds with the receptor, it undergoes a conformational change, enabling it to interact with the G protein. Enzyme-linked receptors, on the other hand, have a cytosolic domain that either has intrinsic enzyme activity or associates directly with an enzyme, and their activation directly triggers a series of enzymatic reactions, leading to a cellular response.
- G Protein Coupled Receptors vs Receptor Tyrosine Kinases
- Heteromeric G Protein vs Monomeric G Protein
- Ionotropic vs Metabotropic Receptors
- Enzyme vs Hormone
- Enzyme vs Protein
- Allosteric vs Non-allosteric Enzymes
- Endocytosis vs Receptor Mediated Endocytosis
- Internal Receptors vs Cell Surface Receptors
- Adrenergic vs Cholinergic Receptors
- Receptor vs Effector
- H1 vs H2 Receptors
- B Cell Receptor vs T Cell Receptor
- D1 vs D2 Receptors
- Alpha vs Beta Receptors
- Enzyme vs Coenzyme
- Enzyme Inhibitor vs Enzyme Inducer
- Cell Immobilization vs Enzyme Immobilization
- Gustatory Receptors vs Olfactory Receptors
- Enzymatic vs Nonenzymatic Reaction