1zsh
From Proteopedia
(New page: 200px<br /><applet load="1zsh" size="450" color="white" frame="true" align="right" spinBox="true" caption="1zsh, resolution 2.9Å" /> '''Crystal structure of ...) |
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| - | [[Image:1zsh.gif|left|200px]]<br /><applet load="1zsh" size=" | + | [[Image:1zsh.gif|left|200px]]<br /><applet load="1zsh" size="350" color="white" frame="true" align="right" spinBox="true" |
caption="1zsh, resolution 2.9Å" /> | caption="1zsh, resolution 2.9Å" /> | ||
'''Crystal structure of bovine arrestin-2 in complex with inositol hexakisphosphate (IP6)'''<br /> | '''Crystal structure of bovine arrestin-2 in complex with inositol hexakisphosphate (IP6)'''<br /> | ||
==Overview== | ==Overview== | ||
| - | Interactions between arrestins and phosphoinositides have been reported to | + | Interactions between arrestins and phosphoinositides have been reported to regulate multiple membrane-associated signaling and trafficking events including clathrin-mediated endocytosis and light adaptation in Drosophila. Arrestins have been proposed to have nuclear and cytosolic functions as well, although the ligand dependence of these functions has not been investigated. Here we characterize the structural, molecular, and cellular interactions between arrestin-2 and inositol hexakisphosphate (inositol 1,2,3,4,5,6-hexakisphosphate (IP(6))). The crystal structure of the arrestin-2.IP(6) complex was solved to 2.9 A with crystal lattice contacts suggesting two sites on a protein monomer mediating IP(6) binding. Mutagenesis coupled to isothermal titration calorimetry and tritiated IP(6) binding assays confirmed two-site binding with a low affinity IP(6)-binding site in the N-domain and a high affinity site in the C-domain. Native gel electrophoresis, gel filtration, and analytical ultracentrifugation demonstrated the ability of IP(6) to promote arrestin-2 oligomerization via the two crystallographically defined ligand-binding locations. In addition, analysis in mammalian cells revealed that arrestin-2 not only undergoes homo-oligomerization, but it can also hetero-oligomerize with arrestin-3 in a manner that depends on IP(6)-binding sites. Mutation of either IP(6)-binding site in arrestin-2 disrupted oligomerization while interactions with known binding partners including clathrin, AP-2, and ERK2 were maintained. Subcellular localization studies showed that arrestin-2 oligomers are primarily cytoplasmic, whereas arrestin-2 monomers displayed increased nuclear localization. Thus, by promoting cytosolic oligomerization, IP(6) binding is proposed to be a negative regulator of interactions of arrestin with plasma membrane and nuclear signaling proteins. |
==About this Structure== | ==About this Structure== | ||
| - | 1ZSH is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Bos_taurus Bos taurus] with MG and IHP as [http://en.wikipedia.org/wiki/ligands ligands]. Full crystallographic information is available from [http:// | + | 1ZSH is a [http://en.wikipedia.org/wiki/Single_protein Single protein] structure of sequence from [http://en.wikipedia.org/wiki/Bos_taurus Bos taurus] with <scene name='pdbligand=MG:'>MG</scene> and <scene name='pdbligand=IHP:'>IHP</scene> as [http://en.wikipedia.org/wiki/ligands ligands]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1ZSH OCA]. |
==Reference== | ==Reference== | ||
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[[Category: Bos taurus]] | [[Category: Bos taurus]] | ||
[[Category: Single protein]] | [[Category: Single protein]] | ||
| - | [[Category: Benovic, J | + | [[Category: Benovic, J L.]] |
[[Category: Brenner, C.]] | [[Category: Brenner, C.]] | ||
| - | [[Category: Kim, Y | + | [[Category: Kim, Y M.]] |
| - | [[Category: Milano, S | + | [[Category: Milano, S K.]] |
| - | [[Category: Stefano, F | + | [[Category: Stefano, F P.]] |
[[Category: IHP]] | [[Category: IHP]] | ||
[[Category: MG]] | [[Category: MG]] | ||
| Line 24: | Line 24: | ||
[[Category: signal transduction]] | [[Category: signal transduction]] | ||
| - | ''Page seeded by [http:// | + | ''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Thu Feb 21 16:18:40 2008'' |
Revision as of 14:18, 21 February 2008
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Crystal structure of bovine arrestin-2 in complex with inositol hexakisphosphate (IP6)
Overview
Interactions between arrestins and phosphoinositides have been reported to regulate multiple membrane-associated signaling and trafficking events including clathrin-mediated endocytosis and light adaptation in Drosophila. Arrestins have been proposed to have nuclear and cytosolic functions as well, although the ligand dependence of these functions has not been investigated. Here we characterize the structural, molecular, and cellular interactions between arrestin-2 and inositol hexakisphosphate (inositol 1,2,3,4,5,6-hexakisphosphate (IP(6))). The crystal structure of the arrestin-2.IP(6) complex was solved to 2.9 A with crystal lattice contacts suggesting two sites on a protein monomer mediating IP(6) binding. Mutagenesis coupled to isothermal titration calorimetry and tritiated IP(6) binding assays confirmed two-site binding with a low affinity IP(6)-binding site in the N-domain and a high affinity site in the C-domain. Native gel electrophoresis, gel filtration, and analytical ultracentrifugation demonstrated the ability of IP(6) to promote arrestin-2 oligomerization via the two crystallographically defined ligand-binding locations. In addition, analysis in mammalian cells revealed that arrestin-2 not only undergoes homo-oligomerization, but it can also hetero-oligomerize with arrestin-3 in a manner that depends on IP(6)-binding sites. Mutation of either IP(6)-binding site in arrestin-2 disrupted oligomerization while interactions with known binding partners including clathrin, AP-2, and ERK2 were maintained. Subcellular localization studies showed that arrestin-2 oligomers are primarily cytoplasmic, whereas arrestin-2 monomers displayed increased nuclear localization. Thus, by promoting cytosolic oligomerization, IP(6) binding is proposed to be a negative regulator of interactions of arrestin with plasma membrane and nuclear signaling proteins.
About this Structure
1ZSH is a Single protein structure of sequence from Bos taurus with and as ligands. Full crystallographic information is available from OCA.
Reference
Nonvisual arrestin oligomerization and cellular localization are regulated by inositol hexakisphosphate binding., Milano SK, Kim YM, Stefano FP, Benovic JL, Brenner C, J Biol Chem. 2006 Apr 7;281(14):9812-23. Epub 2006 Jan 26. PMID:16439357
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