Critical amino acid residues determine the binding affinity and the Ca 2+ release efficacy of maurocalcine in skeletal muscle cells

Eric Estève, Sophia Smida-Rezgui, S. Sárközi, C. Szegedi, Imed Regaya, Lili Chen, Xavier Altafaj, Herré Rochat, Paul Allen, Isaac N. Pessah, Isabelle Marty, Jean Marc Sabatier, I. Jóna, Michel De Waard, Michel Ronjat

Research output: Article

37 Citations (Scopus)

Abstract

Maurocalcine (MCa) is a 33 amino acid residue peptide toxin isolated from the scorpion Scorpio maurus palmatus. MCa and mutated analogues were chemically synthesized, and their interaction with the skeletal muscle ryanodine receptor (RyR1) was studied on purified RyR1, sarcoplasmic reticulum (SR) vesicles, and cultured myotubes. MCa strongly potentiates [3H]ryanodine binding on SR vesicles (7-fold at pCa 5) with an apparent EC50 of 12 nM. MCa decreases the sensitivity of [3H]ryanodine binding to inhibitory high Ca2+ concentrations and increases it to the stimulatory low Ca2+ concentrations. In the presence of MCa, purified RyR1 channels show long-lasting openings characterized by a conductance equivalent to 60% of the full conductance. This effect correlates with a global increase in Ca 2+ efflux as demonstrated by MCa effects on Ca2+ release from SR vesicles. In addition, we show for the first time that external application of MCa to cultured myotubes produces a cytosolic Ca2+ increase due to Ca2+ release from 4-chloro-m-cresol-sensitive intracellular stores. Using various MCa mutants, we identified a critical role of Arg24 for MCa binding onto RyR1. All of the other MCa mutants are still able to modify [3H]ryanodine binding although with a decreased EC50 and a lower stimulation efficacy. All of the active mutants produce both the appearance of a subconductance state and Ca2+ release from SR vesicles. Overall, these data identify some amino acid residues of MCa that support the effect of this toxin on ryanodine binding, RyR1 biophysical properties, and Ca2+ release from SR.

Original languageEnglish
Pages (from-to)37822-37831
Number of pages10
JournalJournal of Biological Chemistry
Volume278
Issue number39
DOIs
Publication statusPublished - szept. 26 2003

Fingerprint

Muscle Cells
Muscle
Skeletal Muscle
Cells
Ryanodine Receptor Calcium Release Channel
Amino Acids
Sarcoplasmic Reticulum
Ryanodine
Skeletal Muscle Fibers
maurocalcine
Scorpions
Peptides

ASJC Scopus subject areas

  • Biochemistry

Cite this

Critical amino acid residues determine the binding affinity and the Ca 2+ release efficacy of maurocalcine in skeletal muscle cells. / Estève, Eric; Smida-Rezgui, Sophia; Sárközi, S.; Szegedi, C.; Regaya, Imed; Chen, Lili; Altafaj, Xavier; Rochat, Herré; Allen, Paul; Pessah, Isaac N.; Marty, Isabelle; Sabatier, Jean Marc; Jóna, I.; De Waard, Michel; Ronjat, Michel.

In: Journal of Biological Chemistry, Vol. 278, No. 39, 26.09.2003, p. 37822-37831.

Research output: Article

Estève, E, Smida-Rezgui, S, Sárközi, S, Szegedi, C, Regaya, I, Chen, L, Altafaj, X, Rochat, H, Allen, P, Pessah, IN, Marty, I, Sabatier, JM, Jóna, I, De Waard, M & Ronjat, M 2003, 'Critical amino acid residues determine the binding affinity and the Ca 2+ release efficacy of maurocalcine in skeletal muscle cells', Journal of Biological Chemistry, vol. 278, no. 39, pp. 37822-37831. https://doi.org/10.1074/jbc.M305798200
Estève, Eric ; Smida-Rezgui, Sophia ; Sárközi, S. ; Szegedi, C. ; Regaya, Imed ; Chen, Lili ; Altafaj, Xavier ; Rochat, Herré ; Allen, Paul ; Pessah, Isaac N. ; Marty, Isabelle ; Sabatier, Jean Marc ; Jóna, I. ; De Waard, Michel ; Ronjat, Michel. / Critical amino acid residues determine the binding affinity and the Ca 2+ release efficacy of maurocalcine in skeletal muscle cells. In: Journal of Biological Chemistry. 2003 ; Vol. 278, No. 39. pp. 37822-37831.
@article{230d7422cfd44cb389bec33f37f3c680,
title = "Critical amino acid residues determine the binding affinity and the Ca 2+ release efficacy of maurocalcine in skeletal muscle cells",
abstract = "Maurocalcine (MCa) is a 33 amino acid residue peptide toxin isolated from the scorpion Scorpio maurus palmatus. MCa and mutated analogues were chemically synthesized, and their interaction with the skeletal muscle ryanodine receptor (RyR1) was studied on purified RyR1, sarcoplasmic reticulum (SR) vesicles, and cultured myotubes. MCa strongly potentiates [3H]ryanodine binding on SR vesicles (7-fold at pCa 5) with an apparent EC50 of 12 nM. MCa decreases the sensitivity of [3H]ryanodine binding to inhibitory high Ca2+ concentrations and increases it to the stimulatory low Ca2+ concentrations. In the presence of MCa, purified RyR1 channels show long-lasting openings characterized by a conductance equivalent to 60{\%} of the full conductance. This effect correlates with a global increase in Ca 2+ efflux as demonstrated by MCa effects on Ca2+ release from SR vesicles. In addition, we show for the first time that external application of MCa to cultured myotubes produces a cytosolic Ca2+ increase due to Ca2+ release from 4-chloro-m-cresol-sensitive intracellular stores. Using various MCa mutants, we identified a critical role of Arg24 for MCa binding onto RyR1. All of the other MCa mutants are still able to modify [3H]ryanodine binding although with a decreased EC50 and a lower stimulation efficacy. All of the active mutants produce both the appearance of a subconductance state and Ca2+ release from SR vesicles. Overall, these data identify some amino acid residues of MCa that support the effect of this toxin on ryanodine binding, RyR1 biophysical properties, and Ca2+ release from SR.",
author = "Eric Est{\`e}ve and Sophia Smida-Rezgui and S. S{\'a}rk{\"o}zi and C. Szegedi and Imed Regaya and Lili Chen and Xavier Altafaj and Herr{\'e} Rochat and Paul Allen and Pessah, {Isaac N.} and Isabelle Marty and Sabatier, {Jean Marc} and I. J{\'o}na and {De Waard}, Michel and Michel Ronjat",
year = "2003",
month = "9",
day = "26",
doi = "10.1074/jbc.M305798200",
language = "English",
volume = "278",
pages = "37822--37831",
journal = "Journal of Biological Chemistry",
issn = "0021-9258",
publisher = "American Society for Biochemistry and Molecular Biology Inc.",
number = "39",

}

TY - JOUR

T1 - Critical amino acid residues determine the binding affinity and the Ca 2+ release efficacy of maurocalcine in skeletal muscle cells

AU - Estève, Eric

AU - Smida-Rezgui, Sophia

AU - Sárközi, S.

AU - Szegedi, C.

AU - Regaya, Imed

AU - Chen, Lili

AU - Altafaj, Xavier

AU - Rochat, Herré

AU - Allen, Paul

AU - Pessah, Isaac N.

AU - Marty, Isabelle

AU - Sabatier, Jean Marc

AU - Jóna, I.

AU - De Waard, Michel

AU - Ronjat, Michel

PY - 2003/9/26

Y1 - 2003/9/26

N2 - Maurocalcine (MCa) is a 33 amino acid residue peptide toxin isolated from the scorpion Scorpio maurus palmatus. MCa and mutated analogues were chemically synthesized, and their interaction with the skeletal muscle ryanodine receptor (RyR1) was studied on purified RyR1, sarcoplasmic reticulum (SR) vesicles, and cultured myotubes. MCa strongly potentiates [3H]ryanodine binding on SR vesicles (7-fold at pCa 5) with an apparent EC50 of 12 nM. MCa decreases the sensitivity of [3H]ryanodine binding to inhibitory high Ca2+ concentrations and increases it to the stimulatory low Ca2+ concentrations. In the presence of MCa, purified RyR1 channels show long-lasting openings characterized by a conductance equivalent to 60% of the full conductance. This effect correlates with a global increase in Ca 2+ efflux as demonstrated by MCa effects on Ca2+ release from SR vesicles. In addition, we show for the first time that external application of MCa to cultured myotubes produces a cytosolic Ca2+ increase due to Ca2+ release from 4-chloro-m-cresol-sensitive intracellular stores. Using various MCa mutants, we identified a critical role of Arg24 for MCa binding onto RyR1. All of the other MCa mutants are still able to modify [3H]ryanodine binding although with a decreased EC50 and a lower stimulation efficacy. All of the active mutants produce both the appearance of a subconductance state and Ca2+ release from SR vesicles. Overall, these data identify some amino acid residues of MCa that support the effect of this toxin on ryanodine binding, RyR1 biophysical properties, and Ca2+ release from SR.

AB - Maurocalcine (MCa) is a 33 amino acid residue peptide toxin isolated from the scorpion Scorpio maurus palmatus. MCa and mutated analogues were chemically synthesized, and their interaction with the skeletal muscle ryanodine receptor (RyR1) was studied on purified RyR1, sarcoplasmic reticulum (SR) vesicles, and cultured myotubes. MCa strongly potentiates [3H]ryanodine binding on SR vesicles (7-fold at pCa 5) with an apparent EC50 of 12 nM. MCa decreases the sensitivity of [3H]ryanodine binding to inhibitory high Ca2+ concentrations and increases it to the stimulatory low Ca2+ concentrations. In the presence of MCa, purified RyR1 channels show long-lasting openings characterized by a conductance equivalent to 60% of the full conductance. This effect correlates with a global increase in Ca 2+ efflux as demonstrated by MCa effects on Ca2+ release from SR vesicles. In addition, we show for the first time that external application of MCa to cultured myotubes produces a cytosolic Ca2+ increase due to Ca2+ release from 4-chloro-m-cresol-sensitive intracellular stores. Using various MCa mutants, we identified a critical role of Arg24 for MCa binding onto RyR1. All of the other MCa mutants are still able to modify [3H]ryanodine binding although with a decreased EC50 and a lower stimulation efficacy. All of the active mutants produce both the appearance of a subconductance state and Ca2+ release from SR vesicles. Overall, these data identify some amino acid residues of MCa that support the effect of this toxin on ryanodine binding, RyR1 biophysical properties, and Ca2+ release from SR.

UR - http://www.scopus.com/inward/record.url?scp=0141621087&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=0141621087&partnerID=8YFLogxK

U2 - 10.1074/jbc.M305798200

DO - 10.1074/jbc.M305798200

M3 - Article

C2 - 12869557

AN - SCOPUS:0141621087

VL - 278

SP - 37822

EP - 37831

JO - Journal of Biological Chemistry

JF - Journal of Biological Chemistry

SN - 0021-9258

IS - 39

ER -