The N-terminal Ca2+-Independent Calmodulin-Binding Site on the Inositol 1,4,5-trisphosphate Receptor Is Responsible for Calmodulin Inhibition, Even Though This Inhibition Requires Ca2+

2004 ◽  
Vol 66 (2) ◽  
pp. 276-284 ◽  
Author(s):  
Nael Nadif Kasri ◽  
Geert Bultynck ◽  
Jeremy Smyth ◽  
Karolina Szlufcik ◽  
Jan B. Parys ◽  
...  
Keyword(s):  
Binding Site ◽  
Calmodulin Binding ◽  
Inositol 1,4,5 Trisphosphate ◽  
Trisphosphate Receptor

scholarly journals Cooperative Formation of the Ligand-binding Site of the Inositol 1,4,5-Trisphosphate Receptor by Two Separable Domains

1999 ◽  
Vol 274 (1) ◽  
pp. 328-334 ◽  
Author(s):  
Fumio Yoshikawa ◽  
Hirohide Iwasaki ◽  
Takayuki Michikawa ◽  
Teiichi Furuichi ◽  
Katsuhiko Mikoshiba
Keyword(s):  
Ligand Binding ◽  
Binding Site ◽  
Ligand Binding Site ◽  
Inositol 1,4,5 Trisphosphate ◽  
Trisphosphate Receptor

scholarly journals Mutational Analysis of the Ligand Binding Site of the Inositol 1,4,5-Trisphosphate Receptor

1996 ◽  
Vol 271 (30) ◽  
pp. 18277-18284 ◽  
Author(s):  
Fumio Yoshikawa ◽  
Mitsuhiro Morita ◽  
Toshiaki Monkawa ◽  
Takayuki Michikawa ◽  
Teiichi Furuichi ◽  
...  
Keyword(s):  
Ligand Binding ◽  
Binding Site ◽  
Mutational Analysis ◽  
Ligand Binding Site ◽  
Inositol 1,4,5 Trisphosphate ◽  
Trisphosphate Receptor

scholarly journals Characterization of a Cytosolic and a Luminal Ca2+Binding Site in the Type I Inositol 1,4,5-Trisphosphate Receptor

1996 ◽  
Vol 271 (43) ◽  
pp. 27005-27012 ◽  
Author(s):  
Ilse Sienaert ◽  
Humbert De Smedt ◽  
Jan B. Parys ◽  
Ludwig Missiaen ◽  
Sara Vanlingen ◽  
...  
Keyword(s):  
Binding Site ◽  
Type I ◽  
Inositol 1,4,5 Trisphosphate ◽  
Trisphosphate Receptor

A new mechanism in the binding between Homer3 EVH1 domain and inositol 1,4,5 trisphosphate receptor suppressor domain

2014 ◽  
Vol 92 (3) ◽  
pp. 163-171
Author(s):  
He Wen ◽  
Hyuk Nam Kwon ◽  
Sunghyouk Park
Keyword(s):  
Binding Site ◽  
Conformational Changes ◽  
Large Scale ◽  
Critical Role ◽  
Binding Assays ◽  
Binding Characteristics ◽  
Binding Partners ◽  
Inositol 1,4,5 Trisphosphate ◽  
Target Binding ◽  
Trisphosphate Receptor

The suppressor domain of inositol 1,4,5 trisphosphate receptor (IP3R) has critical roles in regulating the calcium channel by interacting with many binding partners. The residue 49–53 (PPKKF) of the suppressor domain was suggested to be a canonical Homer EVH1 domain binding site and is also the first a part of calmodulin (CaM) binding site. As CaM-binding of the suppressor domain has been shown to involve large-scale conformational changes, we studied the binding characteristics of the Homer EVH1-suppressor domain with NMR spectroscopy and biochemical pull-down assays for mutants. Our data show that the suppressor domain employs the PPKKF motif in a similar but subtly different way compared to previously characterized interactions, and that the suppressor domain does not undergo large-scale conformational changes. Chemical shift assignments of the Homer3 EVH1 domain found that a new set of residues, located at the opposite side of the previously reported binding site, is also involved in binding, which was confirmed by mutant binding assays. Further analysis suggests that F40 in the new binding sites may have a critical role as a conformational lock-switch in Homer-target binding. The proposed mechanism is implicated in the signaling network involving calcium channels.

scholarly journals The inositol 1,4,5-trisphosphate receptor binding sites of platelet membranes. pH-dependency, inhibition by polymeric sulphates, and the possible presence of arginine at the binding site

1990 ◽  
Vol 267 (2) ◽  
pp. 297-302 ◽  
Author(s):  
F O'Rourke ◽  
M B Feinstein
Keyword(s):  
Binding Site ◽  
Human Platelets ◽  
Active Centre ◽  
Site Model ◽  
Ph Values ◽  
Platelet Membranes ◽  
Ph Dependency ◽  
Binding Data ◽  
Inositol 1,4,5 Trisphosphate ◽  
Trisphosphate Receptor

The present study was initiated to characterize the inositol 1,4,5-trisphosphate (InsP3)-binding site in human platelets that is involved in Ca2+ release. InsP3 binding to platelet membranes was measured in two ways; (1) by displacement of labelled InsP3 with unlabelled InsP3, as in previous studies, and (2) directly, using only radioactive InsP3 as ligand, over the concentration range 0.25-100 nM. At physiological pH (7.1) the binding data were best fitted by a model for a single saturable binding site, with KD = 11.8 nM and Bmax. = 1.4 pmol/mg of protein. At alkaline pH values (8.3 and 9.4) binding was best fitted by a two-site model, the second site being of higher affinity (KD = 0.75-1.2 nM) but lower concentration (Bmax. = 0.195-0.6 pmol/mg of protein). All binding of InsP3 was blocked by polymeric sulphates (heparin, dextran sulphate, polyvinyl sulphate) regardless of pH. The specific arginine-modifying reagent p-hydroxyphenylglyoxal irreversibly blocked InsP3 binding, suggesting the presence of arginine at the recognition site for InsP3 binding. NN′-dicyclohexylcarbodi-imide (DCCD) and 1-ethyl-3-(3-dimethylaminopropyl)carbodi-imide (ECCD), which are carboxy-group-specific reagents, blocked Ca2+ release, but not InsP3 binding, indicating the existence of another site that regulates Ca2+ release apart from the active centre for InsP3.

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