Dataset Information

Both basic and acidic amino acid residues of IpTx(a) are involved in triggering substate of RyR1.

ABSTRACT: Imperatoxin A (IpTx(a)) is known to modify the gating of skeletal ryanodine receptor (RyR1). In this paper, the ability of charged aa residues of IpTx(a) to induce substate of native RyR1 in HSR was examined. Our results show that the basic residues (e.g., Lys¹?, Lys²?, Lys²², Arg²³, and Arg²?) are important for producing substate of RyR1. In addition, other basic residues (e.g., Lys³?, Arg³¹, and Arg³³ near the C-terminus and some acidic residues (e.g., Glu²?, Asp¹³, and Asp²) are also involved in the generation of substate. Residues such as Lys? and Thr²? may be involved in the self-regulation of substate of RyR1, since alanine substitution of the aa residues led to a drastic conversion to the substate. The modifications of the channel gating by the wild-type and mutant toxins were similar in purified RyR1. Taken together, the specific charge distributions on the surface of IpTx(a) are essential for regulation of the channel gating of RyR1.

SUBMITTER: Seo IR

PROVIDER: S-EPMC3192407 | biostudies-literature | 2011

REPOSITORIES: biostudies-literature

ACCESS DATA

Publications

Both basic and acidic amino acid residues of IpTx(a) are involved in triggering substate of RyR1.

Seo In Ra IR Kang Dae Eun DE Song Dong Woo DW Kim Do Han DH

Journal of biomedicine & biotechnology 20111005

Imperatoxin A (IpTx(a)) is known to modify the gating of skeletal ryanodine receptor (RyR1). In this paper, the ability of charged aa residues of IpTx(a) to induce substate of native RyR1 in HSR was examined. Our results show that the basic residues (e.g., Lys¹⁹, Lys²⁰, Lys²², Arg²³, and Arg²⁴) are important for producing substate of RyR1. In addition, other basic residues (e.g., Lys³⁰, Arg³¹, and Arg³³ near the C-terminus and some acidic residues (e.g., Glu²⁹, Asp¹³, and Asp²) are also involved ...[more]

PMID: 22007141

Similar Datasets

Project description:GPR55 is a newly deorphanized class A G-protein-coupled receptor that has been implicated in inflammatory pain, neuropathic pain, metabolic disorder, bone development, and cancer. Few potent GPR55 ligands have been identified to date. This is largely due to an absence of information about salient features of GPR55, such as residues important for signaling and residues implicated in the GPR55 signaling cascade. The goal of this work was to identify residues that are key for the signaling of the GPR55 endogenous ligand, l-?-lysophosphatidylinositol (LPI), as well as the signaling of the GPR55 agonist, ML184 {CID 2440433, 3-[4-(2,3-dimethylphenyl)piperazine-1-carbonyl]-N,N-dimethyl-4-pyrrolidin-1-ylbenzenesulfonamide}. Serum response element (SRE) and serum response factor (SRF) luciferase assays were used as readouts for studying LPI and ML184 signaling at the GPR55 mutants. A GPR55 R* model based on the recent ?-opioid receptor (DOR) crystal structure was used to interpret the resultant mutation data. Two residues were found to be crucial for agonist signaling at GPR55, K2.60 and E3.29, suggesting that these residues form the primary interaction site for ML184 and LPI at GPR55. Y3.32F, H(170)F, and F6.55A/L mutation results suggested that these residues are part of the orthosteric binding site for ML184, while Y3.32F and H(170)F mutation results suggest that these two residues are part of the LPI binding pocket. Y3.32L, M3.36A, and F6.48A mutation results suggest the importance of a Y3.32/M3.36/F6.48 cluster in the GPR55 signaling cascade. C(10)A and C(260)A mutations suggest that these residues form a second disulfide bridge in the extracellular domain of GPR55, occluding ligand extracellular entry in the TMH1-TMH7 region of GPR55. Taken together, these results provide the first set of discrete information about GPR55 residues important for LPI and ML184 signaling and for GPR55 activation. This information should aid in the rational design of next-generation GPR55 ligands and the creation of the first high-affinity GPR55 radioligand, a tool that is sorely needed in the field.

Dataset Information

Both basic and acidic amino acid residues of IpTx(a) are involved in triggering substate of RyR1.

Publications

Both basic and acidic amino acid residues of IpTx(a) are involved in triggering substate of RyR1.

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets