PI3K: Difference between revisions
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Phosphatidylinositol 3-kinase (PI3K)& | <p>Phosphatidylinositol 3-kinase (PI3K) adds a phosphate group to the 3C position in a inosital ring in <a href="Phosphatidylinositol">Phosphatidylinositol</a>. | ||
</p><p>For example: | |||
For example: | </p><p><a href="Phosphatidylinositol 4,5-bisphosphate">PI-4,5-phosphate</a> (PIP<sub>2</sub>) + ATP ----> PI-3,4, 5-bisphosphate (PIP<sub>3</sub>) + ADP<br /> | ||
</p><p>This in the context of the <a href="Insulin">Insulin</a> pathway allows the resulting <a href="Phosphatidylinositol 4,5-bisphosphate">PIP<sub>3</sub></a> to remain bound to the plasma membrane. This initiates a signal cascade which can cause <a href="Glut 4">GLUT 4</a> translocation, decreased synthesis of glycerol and fatty acids, increased <a href="Glycogen synthesis">glycogen synthesis</a> and increased <a href="Proteins">protein</a> synthesis in the cell. | |||
</p><p>The enzyme has 2 subunits: | |||
</p> | |||
This in the context of the | <ol><li>Regulatory subunit, p85 (85 kDa), contains 2 <a href="SH2 domains">SH2 domains</a> and 1 <a href="SH3 domains">SH3 domain</a>. | ||
</li><li>Catalytic subunit, p110 (110 kDa). | |||
The enzyme has 2 subunits: | </li></ol> | ||
<p>The <a href="SH2 domains">SH2 domain</a> in the context of the <a href="Insulin">Insulin</a> pathway binds p85 to phosphorylated <a href="Tyrosine">tyrosines</a> on the <a href="Insulin receptor substrate">Insulin receptor substrate</a> (<a href="Insulin receptor substrate">IRS</a>). The <a href="SH3 domains">SH3 domain</a> targets the <a href="Proline">proline rich</a> section of p85 binding both regulatory and catalytic subunits together. | |||
</p><p>  | |||
</p><p>There are three classes of P13K enzymes. Class I can phosphorylate 3 different substrates: non-phosphorylated phosphatidylinositol, inositol monophosphate and bisphosphate inositol. The catalytic subunit is p100 and the regulatory subunit is p85. This class of P13K are associated with being of <a href="Oncogenes">oncogenic</a> nature, as the catalytic subunit can become mutated, unlike class II and III.<span class="fck_mw_ref">Phosphatidylinositol 3-kinase (PI3K): The Oncoprotein Peter K. Vogt PubMed (accessed 22/10/2018) https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2955792/</span> | |||
</p> | |||
The | |||
& | |||
There are three classes of P13K enzymes. Class I can phosphorylate 3 different substrates: non-phosphorylated phosphatidylinositol, inositol monophosphate and bisphosphate inositol. The catalytic subunit is p100 and the regulatory subunit is p85. This class of P13K are associated with being of | |||
Revision as of 14:23, 22 October 2018
Phosphatidylinositol 3-kinase (PI3K) adds a phosphate group to the 3C position in a inosital ring in <a href="Phosphatidylinositol">Phosphatidylinositol</a>.
For example:
<a href="Phosphatidylinositol 4,5-bisphosphate">PI-4,5-phosphate</a> (PIP2) + ATP ----> PI-3,4, 5-bisphosphate (PIP3) + ADP
This in the context of the <a href="Insulin">Insulin</a> pathway allows the resulting <a href="Phosphatidylinositol 4,5-bisphosphate">PIP3</a> to remain bound to the plasma membrane. This initiates a signal cascade which can cause <a href="Glut 4">GLUT 4</a> translocation, decreased synthesis of glycerol and fatty acids, increased <a href="Glycogen synthesis">glycogen synthesis</a> and increased <a href="Proteins">protein</a> synthesis in the cell.
The enzyme has 2 subunits:
- Regulatory subunit, p85 (85 kDa), contains 2 <a href="SH2 domains">SH2 domains</a> and 1 <a href="SH3 domains">SH3 domain</a>.
- Catalytic subunit, p110 (110 kDa).
The <a href="SH2 domains">SH2 domain</a> in the context of the <a href="Insulin">Insulin</a> pathway binds p85 to phosphorylated <a href="Tyrosine">tyrosines</a> on the <a href="Insulin receptor substrate">Insulin receptor substrate</a> (<a href="Insulin receptor substrate">IRS</a>). The <a href="SH3 domains">SH3 domain</a> targets the <a href="Proline">proline rich</a> section of p85 binding both regulatory and catalytic subunits together.
There are three classes of P13K enzymes. Class I can phosphorylate 3 different substrates: non-phosphorylated phosphatidylinositol, inositol monophosphate and bisphosphate inositol. The catalytic subunit is p100 and the regulatory subunit is p85. This class of P13K are associated with being of <a href="Oncogenes">oncogenic</a> nature, as the catalytic subunit can become mutated, unlike class II and III.Phosphatidylinositol 3-kinase (PI3K): The Oncoprotein Peter K. Vogt PubMed (accessed 22/10/2018) https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2955792/