Sandbox Reserved 1473: Difference between revisions

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G-Protein Coupled Receptors (GPCR), also known as 7 transmembrane receptors [because of its 7 constituent alpha helices] are the largest groups of transmembrane protein receptors in eukaryotes. There are many different classes GPCRs depending on the position of their binding sites or the kind of ligands they bind to. There are about six classes of GPCRs and they include the classes A, B, C, D, E, AND F. Beta adrenergic receptors fall the class C with other metabotropic hormones while Rhodopsin (the light sensing cells in our eye) are categorized under class A. All studied GPCRs have a conserved structure that can be subdivided into; the extracellular domain (ECD), which comprises the three extracellular loops (EC1), (EC2), (EC3) and the N-terminal amino groups, the seven spanning helices transmembrane domain (7TM) embedded within the plasma membrane, and the intracellular domains ICD which also comprises the carboxyl-terminal residues and three intracellular loops (ICL1, ICL2, ICL3). The binding of the receptor to a ligand causes a structural change in the intracellular domains that also signals/activates the alpha subunit of a G-protein to exchange GDP for GTP, transducing the signal further downstream.

</StructureSection>

[[Image:Disulfide Linkages.png|thumb|downright=2.1| Disulfide Linkages between the TMD and ECL]]

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[[Image:Terminal.png|thumb|downleft=2.1| Amini and Carboxyl terminal groups]]

~~</StructureSection>~~

G-Protein Coupled Receptors (GPCR), also known as 7 transmembrane receptors [because of its 7 constituent alpha helices] are the largest groups of transmembrane protein receptors in eukaryotes. There are many different classes GPCRs depending on the position of their binding sites or the kind of ligands they bind to. There are about six classes of GPCRs and they include the classes A, B, C, D, E, AND F. Beta adrenergic receptors fall the class C with other metabotropic hormones while Rhodopsin (the light sensing cells in our eye) are categorized under class A. All studied GPCRs have a conserved structure that can be subdivided into; the extracellular domain (ECD), which comprises the three extracellular loops (EC1), (EC2), (EC3) and the N-terminal amino groups, the seven spanning helices transmembrane domain (7TM) embedded within the plasma membrane, and the intracellular domains ICD which also comprises the carboxyl-terminal residues and three intracellular loops (ICL1, ICL2, ICL3). The binding of the receptor to a ligand causes a structural change in the intracellular domains that also signals/activates the alpha subunit of a G-protein to exchange GDP for GTP, transducing the signal further downstream.

For some GPCRs, the ligand binds to a site in the 7TM (certain class A) or both the ECD and the 7TM as in certain class B GPCRs. However, in the Beta Adrenergic receptor, the ligand binds at the the extracellular domain [ECD] which acts like a fly-trap pocket. The transmembrane domain is structurally coupled to the extracellular domain through Disulfide linkages and mutations within this region disrupts the entire structure and function of GPCRs.

The intra cellular domain sits in the cytoplasmic end of the transmembrane domain. This region contains the D/E R Y motif; a conserved region within the ICD that interacts with interacts with intracellular ligands like the G-subunit (activates it) and phosphorylate other kinases as well. The C-terminal domain is structurally independent of the ECD and can adopt functionally discrete conformation in the absence of transmembrane helices. The C-terminal domain regulates the interactions with cytosolic proteins involved in signaling.

Sandbox Reserved 1473: Difference between revisions

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@@ Line 44: / Line 44: @@
 <StructureSection load='2rh1' size='300' side='right' caption='Human Beta adrenergic receptor with bound ligand' scene='80/800652/Showing_ligand/1' >
+G-Protein Coupled Receptors (GPCR), also known as 7 transmembrane receptors [because of its 7 constituent alpha helices] are the largest groups of transmembrane protein receptors in eukaryotes. There are many different classes GPCRs depending on the position of their binding sites or the kind of ligands they bind to. There are about six classes of GPCRs and they include the classes A, B, C, D, E, AND F. Beta adrenergic receptors fall the class C with other metabotropic hormones while Rhodopsin (the light sensing cells in our eye) are categorized under class A. All studied GPCRs have a conserved structure that can be subdivided into; the extracellular domain (ECD), which comprises the three extracellular loops (EC1), (EC2), (EC3) and the N-terminal amino groups, the seven spanning helices transmembrane domain (7TM) embedded within the plasma membrane, and the intracellular domains ICD which also comprises the carboxyl-terminal residues and three intracellular loops (ICL1, ICL2, ICL3). The binding of the receptor to a ligand causes a structural change in the intracellular domains that also signals/activates the alpha subunit of a G-protein to exchange GDP for GTP, transducing the signal further downstream.
+</StructureSection>
 [[Image:Disulfide Linkages.png|thumb|downright=2.1| Disulfide Linkages between the TMD and ECL]]
@@ Line 50: / Line 55: @@
 [[Image:Terminal.png|thumb|downleft=2.1| Amini and Carboxyl terminal groups]]
-</StructureSection>
-G-Protein Coupled Receptors (GPCR), also known as 7 transmembrane receptors [because of its 7 constituent alpha helices] are the largest groups of transmembrane protein receptors in eukaryotes. There are many different classes GPCRs depending on the position of their binding sites or the kind of ligands they bind to. There are about six classes of GPCRs and they include the classes A, B, C, D, E, AND F. Beta adrenergic receptors fall the class C with other metabotropic hormones while Rhodopsin (the light sensing cells in our eye) are categorized under class A. All studied GPCRs have a conserved structure that can be subdivided into; the extracellular domain (ECD), which comprises the three extracellular loops (EC1), (EC2), (EC3) and the N-terminal amino groups, the seven spanning helices transmembrane domain (7TM) embedded within the plasma membrane, and the intracellular domains ICD which also comprises the carboxyl-terminal residues and three intracellular loops (ICL1, ICL2, ICL3). The binding of the receptor to a ligand causes a structural change in the intracellular domains that also signals/activates the alpha subunit of a G-protein to exchange GDP for GTP, transducing the signal further downstream.
 For some GPCRs, the ligand binds to a site in the 7TM (certain class A) or both the ECD and the 7TM as in certain class B GPCRs. However, in the Beta Adrenergic receptor, the ligand binds at the the extracellular domain [ECD] which acts like a fly-trap pocket. The transmembrane domain is structurally coupled to the extracellular domain through Disulfide linkages and mutations within this region disrupts the entire structure and function of GPCRs.
 The intra cellular domain sits in the cytoplasmic end of the transmembrane domain. This region contains the D/E R Y motif; a conserved region within the ICD that interacts with interacts with intracellular ligands like the G-subunit (activates it) and phosphorylate other kinases as well. The C-terminal domain is structurally independent of the ECD and can adopt functionally discrete conformation in the absence of transmembrane helices. The C-terminal domain regulates the interactions with cytosolic proteins involved in signaling.