8emv: Difference between revisions
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The | ==Phospholipase C beta 3 (PLCb3) in solution== | ||
<StructureSection load='8emv' size='340' side='right'caption='[[8emv]], [[Resolution|resolution]] 3.60Å' scene=''> | |||
== Structural highlights == | |||
<table><tr><td colspan='2'>[[8emv]] is a 1 chain structure with sequence from [https://en.wikipedia.org/wiki/Homo_sapiens Homo sapiens]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=8EMV OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=8EMV FirstGlance]. <br> | |||
</td></tr><tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=CA:CALCIUM+ION'>CA</scene></td></tr> | |||
<tr id='resources'><td class="sblockLbl"><b>Resources:</b></td><td class="sblockDat"><span class='plainlinks'>[https://proteopedia.org/fgij/fg.htm?mol=8emv FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=8emv OCA], [https://pdbe.org/8emv PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=8emv RCSB], [https://www.ebi.ac.uk/pdbsum/8emv PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=8emv ProSAT]</span></td></tr> | |||
</table> | |||
== Function == | |||
[https://www.uniprot.org/uniprot/PLCB3_HUMAN PLCB3_HUMAN] The production of the second messenger molecules diacylglycerol (DAG) and inositol 1,4,5-trisphosphate (IP3) is mediated by activated phosphatidylinositol-specific phospholipase C enzymes. | |||
<div style="background-color:#fffaf0;"> | |||
== Publication Abstract from PubMed == | |||
Phospholipase C-betas (PLCbetas) catalyze the hydrolysis of phosphatidylinositol 4, 5-bisphosphate [Formula: see text] into [Formula: see text] [Formula: see text] and [Formula: see text] [Formula: see text]. [Formula: see text] regulates the activity of many membrane proteins, while IP3 and DAG lead to increased intracellular Ca(2+) levels and activate protein kinase C, respectively. PLCbetas are regulated by G protein-coupled receptors through direct interaction with [Formula: see text] and [Formula: see text] and are aqueous-soluble enzymes that must bind to the cell membrane to act on their lipid substrate. This study addresses the mechanism by which [Formula: see text] activates PLCbeta3. We show that PLCbeta3 functions as a slow Michaelis-Menten enzyme ( [Formula: see text] ) on membrane surfaces. We used membrane partitioning experiments to study the solution-membrane localization equilibrium of PLCbeta3. Its partition coefficient is such that only a small quantity of PLCbeta3 exists in the membrane in the absence of [Formula: see text] . When [Formula: see text] is present, equilibrium binding on the membrane surface increases PLCbeta3 in the membrane, increasing [Formula: see text] in proportion. Atomic structures on membrane vesicle surfaces show that two [Formula: see text] anchor PLCbeta3 with its catalytic site oriented toward the membrane surface. Taken together, the enzyme kinetic, membrane partitioning, and structural data show that [Formula: see text] activates PLCbeta by increasing its concentration on the membrane surface and orienting its catalytic core to engage [Formula: see text] . This principle of activation explains rapid stimulated catalysis with low background activity, which is essential to the biological processes mediated by [Formula: see text], IP3, and DAG. | |||
Gbetagamma activates PIP2 hydrolysis by recruiting and orienting PLCbeta on the membrane surface.,Falzone ME, MacKinnon R Proc Natl Acad Sci U S A. 2023 May 16;120(20):e2301121120. doi: , 10.1073/pnas.2301121120. Epub 2023 May 12. PMID:37172014<ref>PMID:37172014</ref> | |||
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.<br> | |||
[[Category: | </div> | ||
<div class="pdbe-citations 8emv" style="background-color:#fffaf0;"></div> | |||
== References == | |||
<references/> | |||
__TOC__ | |||
</StructureSection> | |||
[[Category: Homo sapiens]] | |||
[[Category: Large Structures]] | |||
[[Category: Falzone ME]] | |||
[[Category: MacKinnon R]] |
Revision as of 07:04, 25 May 2023
Phospholipase C beta 3 (PLCb3) in solutionPhospholipase C beta 3 (PLCb3) in solution
Structural highlights
FunctionPLCB3_HUMAN The production of the second messenger molecules diacylglycerol (DAG) and inositol 1,4,5-trisphosphate (IP3) is mediated by activated phosphatidylinositol-specific phospholipase C enzymes. Publication Abstract from PubMedPhospholipase C-betas (PLCbetas) catalyze the hydrolysis of phosphatidylinositol 4, 5-bisphosphate [Formula: see text] into [Formula: see text] [Formula: see text] and [Formula: see text] [Formula: see text]. [Formula: see text] regulates the activity of many membrane proteins, while IP3 and DAG lead to increased intracellular Ca(2+) levels and activate protein kinase C, respectively. PLCbetas are regulated by G protein-coupled receptors through direct interaction with [Formula: see text] and [Formula: see text] and are aqueous-soluble enzymes that must bind to the cell membrane to act on their lipid substrate. This study addresses the mechanism by which [Formula: see text] activates PLCbeta3. We show that PLCbeta3 functions as a slow Michaelis-Menten enzyme ( [Formula: see text] ) on membrane surfaces. We used membrane partitioning experiments to study the solution-membrane localization equilibrium of PLCbeta3. Its partition coefficient is such that only a small quantity of PLCbeta3 exists in the membrane in the absence of [Formula: see text] . When [Formula: see text] is present, equilibrium binding on the membrane surface increases PLCbeta3 in the membrane, increasing [Formula: see text] in proportion. Atomic structures on membrane vesicle surfaces show that two [Formula: see text] anchor PLCbeta3 with its catalytic site oriented toward the membrane surface. Taken together, the enzyme kinetic, membrane partitioning, and structural data show that [Formula: see text] activates PLCbeta by increasing its concentration on the membrane surface and orienting its catalytic core to engage [Formula: see text] . This principle of activation explains rapid stimulated catalysis with low background activity, which is essential to the biological processes mediated by [Formula: see text], IP3, and DAG. Gbetagamma activates PIP2 hydrolysis by recruiting and orienting PLCbeta on the membrane surface.,Falzone ME, MacKinnon R Proc Natl Acad Sci U S A. 2023 May 16;120(20):e2301121120. doi: , 10.1073/pnas.2301121120. Epub 2023 May 12. PMID:37172014[1] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. References
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