User:LuckiestOtter13/G6B
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Structurally distinct, but functionally similar versions of a protein that comes from the same [[gene]] or very closely related are known as a [[protein isoform]] or known as a "protein variant". Many function similarly or biologically similar, there are some isoform have unique functions. |
Structurally distinct, but functionally similar versions of a protein that comes from the same [[gene]] or very closely related are known as a [[protein isoform]] or known as a "protein variant". Many function similarly or biologically similar, there are some isoform have unique functions. |
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G6b-B is one of two major membrane bound isoforms, which contains a extracellular N-terminal Ig-like domain and transmembrane segment.{{Cite journal |last=Newland |first=Stephen A. |last2=Macaulay |first2=Iain C. |last3=Floto |first3=Andres R. |last4=de Vet |first4=Edwin C. |last5=Ouwehand |first5=Willem H. |last6=Watkins |first6=Nicholas A. |last7=Lyons |first7=Paul A. |last8=Campbell |first8=Duncan R. |date=2007-06-01 |title=The novel inhibitory receptor G6B is expressed on the surface of platelets and attenuates platelet function in vitro |url=https://ashpublications.org/blood/article/109/11/4806/23066/The-novel-inhibitory-receptor-G6B-is-expressed-on |journal=Blood |language=en |volume=109 |issue=11 |pages=4806–4809 |doi=10.1182/blood-2006-09-047449 |issn=0006-4971 |archive-url=http://web.archive.org/web/20250418104815/https://ashpublications.org/blood/article/109/11/4806/23066/The-novel-inhibitory-receptor-G6B-is-expressed-on |archive-date=2025-04-18}} This isoform is containing of two immunoreceptors tyrosine-based inhibitory motifs (ITIMs) in the cytoplasmic tail that is not found in the G6b-A isoform. G6b-A isoform is different from G6b-B isoform by the cytoplasmic tail that is not found in G6b-A. G6b-B is binding the protein tyrosine phosphatases SHP-1 and SHP-2 when pervanadate-induced phosphorylation of the ITIMs happens. What allows for the interaction between G6b with SHP-1 and SHP-2 is the phosphorylation of tyrosine 211 that can be seen on the cytoplasmic tail.{{Cite journal |last=de Vet |first=Edwin C. J. M. |last2=Aguado |first2=Begoña |last3=Campbell |first3=R. Duncan |date=2001-11-09 |title=G6b, a Novel Immunoglobulin Superfamily Member Encoded in the Human Major Histocompatibility Complex, Interacts with SHP-1 and SHP-2* |url=https://www.sciencedirect.com/science/article/pii/S0021925819830636 |journal=Journal of Biological Chemistry |volume=276 |issue=45 |pages=42070–42076 |doi=10.1074/jbc.M103214200 |issn=0021-9258}} |
G6b-B is one of two major membrane bound isoforms, which contains a extracellular N-terminal Ig-like domain and transmembrane segment. |
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G6b-B contains the two tyrosine residues in the cytoplasmic tail (Tyr-211 and Tyr-237) that with site directed mutageniss, shows that suggestion that only Tyr-211 gets phosphorylated when pervanadate stimulation of COS-7 cells happens. This Tyr-211 is responsible for SHP-1 and SHP-2 binding. Phosphorylation of Tyr-237 from G6b-B cytoplasmic tail is not detectable, as there is a possibility that the phosphorylation of Tyr-237 is dependent on prior phosphorylation of the Tyr-211. |
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== Function == |
== Function == |
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The function of G6b it to be a cell-surface receptor that has an inhibitory function that operates in a calcium-independent way. With this G6b has been seen to have a novel inhibitory receptor as well that is found on the surface of platelets.{{Cite journal |last=Newland |first=Stephen A. |last2=Macaulay |first2=Iain C. |last3=Floto |first3=Andres R. |last4=de Vet |first4=Edwin C. |last5=Ouwehand |first5=Willem H. |last6=Watkins |first6=Nicholas A. |last7=Lyons |first7=Paul A. |last8=Campbell |first8=Duncan R. |date=2007-06-01 |title=The novel inhibitory receptor G6B is expressed on the surface of platelets and attenuates platelet function in vitro |url=https://ashpublications.org/blood/article/109/11/4806/23066/The-novel-inhibitory-receptor-G6B-is-expressed-on |journal=Blood |language=en |volume=109 |issue=11 |pages=4806–4809 |doi=10.1182/blood-2006-09-047449 |issn=0006-4971}} G6b's function has a crucial connection to the identification of the extracellular ligand, as the protein ligands for the Ig superfamily members are usually but not always other Ig superfamily members.{{Cite journal |last=de Vet |first=Edwin C. J. M. |last2=Newland |first2=Stephen A. B. |last3=Lyons |first3=Paul A. |last4=Aguado |first4=Begoña |last5=Campbell |first5=R. Duncan |date=2005-04-25 |title=The cell surface receptor G6b, a member of the immunoglobulin superfamily, binds heparin |url=https://www.sciencedirect.com/science/article/pii/S0014579305003728 |journal=FEBS Letters |volume=579 |issue=11 |pages=2355–2358 |doi=10.1016/j.febslet.2005.03.032 |issn=0014-5793}} Interactions between the Ig superfamily members and the ligands connected to them, typically have a low affinity, which makes the identification of ligands in experiments challenging. The extracellular domain of the G6b protein shows that there is evidence |
The function of G6b it to be a cell-surface receptor that has an inhibitory function that operates in a calcium-independent way. With this G6b has been seen to have a novel inhibitory receptor as well that is found on the surface of platelets.{{Cite journal |last=Newland |first=Stephen A. |last2=Macaulay |first2=Iain C. |last3=Floto |first3=Andres R. |last4=de Vet |first4=Edwin C. |last5=Ouwehand |first5=Willem H. |last6=Watkins |first6=Nicholas A. |last7=Lyons |first7=Paul A. |last8=Campbell |first8=Duncan R. |date=2007-06-01 |title=The novel inhibitory receptor G6B is expressed on the surface of platelets and attenuates platelet function in vitro |url=https://ashpublications.org/blood/article/109/11/4806/23066/The-novel-inhibitory-receptor-G6B-is-expressed-on |journal=Blood |language=en |volume=109 |issue=11 |pages=4806–4809 |doi=10.1182/blood-2006-09-047449 |issn=0006-4971}} G6b's function has a crucial connection to the identification of the extracellular ligand, as the protein ligands for the Ig superfamily members are usually but not always other Ig superfamily members.{{Cite journal |last=de Vet |first=Edwin C. J. M. |last2=Newland |first2=Stephen A. B. |last3=Lyons |first3=Paul A. |last4=Aguado |first4=Begoña |last5=Campbell |first5=R. Duncan |date=2005-04-25 |title=The cell surface receptor G6b, a member of the immunoglobulin superfamily, binds heparin |url=https://www.sciencedirect.com/science/article/pii/S0014579305003728 |journal=FEBS Letters |volume=579 |issue=11 |pages=2355–2358 |doi=10.1016/j.febslet.2005.03.032 |issn=0014-5793}} Interactions between the Ig superfamily members and the ligands connected to them, typically have a low affinity, which makes the identification of ligands in experiments challenging. The extracellular domain of the G6b protein shows that there is evidence that the binding to heparin is mainly electrostatic. However, the protein ligand of the extracellular part of the G6b has not been identified yet, there is a possibility that the binding of heparin plays an essential role in the G6b biological function. |
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== Expression == |
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The expression of G6b-A and G6b-B has been shown to be expressed on the surface of resting RNA and mRNA platelets. G6b-B is the only G6b isoform when analyzed to appear to be efficiently phosphorylated when [[COS-7]] cells and [[K562 cells|K562]] cells are expressing recombinant protein that are treated with pervanadate. |
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This will allow for the classification of this isoform as new member of the family of inhibitory receptors.{{Dashboard.wikiedu.org draft template/about this sandbox}} |
This will allow for the classification of this isoform as new member of the family of inhibitory receptors.{{Dashboard.wikiedu.org draft template/about this sandbox}} |
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