Sandbox Reserved 427: Difference between revisions

Line 35:

===Binding Interactions===

~~3loh~~

~~transmembrane receptor activated in the presence of insulin, a member of the tyrosine kinase class of receptor proteins~~

~~Tyrosine Kinases~~ in ~~General~~

The insulin receptor's (IR) main substrate is insulin, which is referred to as insulin receptor substrate 1 (IRS-1). As insulin binds to the IR, the IR is phosphorylated. Phosphorylation of tyrosine residues in the IR leads to an increase in the glucose transporter (Glut-4) which has a high affinity for glucose molecules. This occurs mainly in muscle and adipose (fat) tissues where glucose uptake is most needed. This increase in Glut-4 causes an increase in glucose uptake from blood. Simply stated, 3loh is activated by insulin (IRS-1) which signals for an increase in Glut-4. Glut-4 finds its way to the cell surface where it can perform its function and transport glucose into the cell.

~~Class of receptor proteins that add~~ a ~~phosphate group~~ to ~~a tyrosine on their specific substrate~~.

The binding mechanism and site are not completely understood. What is known, however, is that insulin is able to bind at two different locations on each monomer of the insulin receptor. Since there are two monomers in the biologically functional ectodomain, there are in total four locations available for binding and interaction. These locations are explained in the Introduction section of this page. Current literature describes the locations for insulin binding as follows: the region between L1 and Fn2 as site 1, the region involving L2, Fn1, and Fn2 as site 2. Based on knowledge of the structure of the insulin receptor (it is a dimer with mirrored symmetry), one can see that the site 1 of one monomer will be adjacent to site 2 on the second. In order to eliminate confusion, most literature refer to the binding sites across from site 1 and site 2 as site 2' and site 1', respectively (Green Scene with labels).

Recent research has indicated that it may be possible that both the structure of the insulin receptor and the structure of insulin itself may change upon binding. It is also thought that insulin may posses multiple surfaces that are capable of binding to the functional ectodomain.

The insulin receptor's main substrate is insulin, which is referred to as insulin receptor substrate 1 (IRS-1). Upon binding to IRS-1, the insulin receptor phosphorylates at least 3 tyrosine residues in IRS-1. These tyrosines are known to be located at residues 1158, 1162, and 1163. Phosphorylation of these 3 tyrosines, and possibly more, leads to an increase in the glucose transporter (Glut-4) which has a high affinity for glucose molecules. This occurs mainly in muscle and adipose tissues where glucose uptake is most needed. This increase in Glut-4 causes an increase in glucose uptake from blood. Simply stated, 3loh is activated by insulin (IRS-1) which signals for an increase in Glut-4. Glut-4 finds its way to the cell surface where it can perform its function (transport glucose into the cell).

~~The binding mechanism and site are not completely understood. What is known, however, is that~~

Green scene of the active site of 3loh. The active site is highlighted in red. <scene name='Sandbox_Reserved_427/Active_site/1'>Active Site</scene>. This green scene is quite complex! Simplify to make your point clearly... Prof T.

Sandbox Reserved 427: Difference between revisions

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@@ Line 35: / Line 35: @@
 ===Binding Interactions===
-loh
-transmembrane receptor activated in the presence of insulin, a member of the tyrosine kinase class of receptor proteins
-Tyrosine Kinases in General
+The insulin receptor's (IR) main substrate is insulin, which is referred to as insulin receptor substrate 1 (IRS-1). As insulin binds to the IR, the IR is phosphorylated. Phosphorylation of tyrosine residues in the IR leads to an increase in the glucose transporter (Glut-4) which has a high affinity for glucose molecules. This occurs mainly in muscle and adipose (fat) tissues where glucose uptake is most needed. This increase in Glut-4 causes an increase in glucose uptake from blood. Simply stated, 3loh is activated by insulin (IRS-1) which signals for an increase in Glut-4. Glut-4 finds its way to the cell surface where it can perform its function and transport glucose into the cell.
-Class of receptor proteins that add a phosphate group to a tyrosine on their specific substrate.
+The binding mechanism and site are not completely understood. What is known, however, is that insulin is able to bind at two different locations on each monomer of the insulin receptor. Since there are two monomers in the biologically functional ectodomain, there are in total four locations available for binding and interaction. These locations are explained in the Introduction section of this page. Current literature describes the locations for insulin binding as follows: the region between L1 and Fn2 as site 1, the region involving L2, Fn1, and Fn2 as site 2. Based on knowledge of the structure of the insulin receptor (it is a dimer with mirrored symmetry), one can see that the site 1 of one monomer will be adjacent to site 2 on the second. In order to eliminate confusion, most literature refer to the binding sites across from site 1 and site 2 as site 2' and site 1', respectively (Green Scene with labels).
+Recent research has indicated that it may be possible that both the structure of the insulin receptor and the structure of insulin itself may change upon binding. It is also thought that insulin may posses multiple surfaces that are capable of binding to the functional ectodomain.
-The insulin receptor's main substrate is insulin, which is referred to as insulin receptor substrate 1 (IRS-1). Upon binding to IRS-1, the insulin receptor phosphorylates at least 3 tyrosine residues in IRS-1. These tyrosines are known to be located at residues 1158, 1162, and 1163. Phosphorylation of these 3 tyrosines, and possibly more, leads to an increase in the glucose transporter (Glut-4) which has a high affinity for glucose molecules. This occurs mainly in muscle and adipose tissues where glucose uptake is most needed. This increase in Glut-4 causes an increase in glucose uptake from blood. Simply stated, 3loh is activated by insulin (IRS-1) which signals for an increase in Glut-4. Glut-4 finds its way to the cell surface where it can perform its function (transport glucose into the cell).
-The binding mechanism and site are not completely understood. What is known, however, is that
 Green scene of the active site of 3loh. The active site is highlighted in red. <scene name='Sandbox_Reserved_427/Active_site/1'>Active Site</scene>. This green scene is quite complex! Simplify to make your point clearly... Prof T.