Structural basis of drug binding to L Ca2+ channels

Striessnig, Jörg; Grabner, Manfred; Mitterdorfer, Jörg; Hering, Steffen; Sinnegger, Martina J.; Glossmann, Hartmut

doi:10.1016/s0165-6147(98)01171-7

Cited by 252 publications

(187 citation statements)

References 39 publications

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“…The affinity of the Ca v 1.2 channel for DHPs is lowered 100-fold by mutation of Tyr-1485, Met-1486, and Ile-1493 in the IVS6 segment (39) and is lost upon mutation of Thr-1061 in the IIIS5 segment (see Refs. 3,5,and 20). It is possible that the new channel has an altered IVS6 segment but retained other parts of the DHP-binding site.…”

Section: Resultsmentioning

confidence: 99%

Functional Embryonic Cardiomyocytes after Disruption of the L-type α1C (Ca 1.2) Calcium Channel Gene in the Mouse

Seisenberger¹,

Specht²,

Welling³

et al. 2000

Journal of Biological Chemistry

255

207

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Section: Resultsmentioning

confidence: 99%

Functional Embryonic Cardiomyocytes after Disruption of the L-type α1C (Ca 1.2) Calcium Channel Gene in the Mouse

Seisenberger¹,

Specht²,

Welling³

et al. 2000

Journal of Biological Chemistry

255

207

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“…Mutagenesis was performed using the QuikChangeXL kit (Stratagene) according to the manufacturer's instructions. This DHP-insensitive mutant contained mutations at the critical residues Thr1066 in IIIS5 [4,14,15], as well as Phe 1463, Met1464, and Iso1471 in IVS6 [3][4][5]. These mutations have previously been shown to decrease the affinity of α 1c for dihydropyridines by over 100-fold, without significant effects on the biophysical properties of the channel [3].…”

Section: Experimental Procedures α 1c-d-plasmid Preparationmentioning

confidence: 99%

“…The largest component is the pore-forming α 1 subunit (∼220 kDa), the critical determinant of most functional properties of the channel, including voltage-dependent gating, Ca 2+ permeability, Ca 2+ -dependent inactivation [1,2], and inhibition by the three principal classes of Ca 2+ channel antagonists [3][4][5].…”

Section: Introductionmentioning

confidence: 99%

Reverse engineering the L-type Ca2+ channel α1c subunit in adult cardiac myocytes using novel adenoviral vectors

Ganesan

O’Rourke

Maack

et al. 2005

Biochemical and Biophysical Research Communications

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The α 1c subunit of the cardiac L-type Ca 2+ channel, which contains the channel pore, voltage-and Ca 2+ -dependent gating structures, and drug binding sites, has been well studied in heterologous expression systems, but many aspects of L-type Ca 2+ channel behavior in intact cardiomyocytes remain poorly characterized. Here, we develop adenoviral constructs with E1, E3 and fiber gene deletions, to allow incorporation of full-length α 1c gene cassettes into the adenovirus backbone. Wildtype (α 1c-wt ) and mutant (α 1c-D-) Ca 2+ channel adenoviruses were constructed. The α 1c-D-contained four point substitutions at amino acid residues known to be critical for dihydropyridine binding. Both α 1c-wt and α 1c-D-expressed robustly in A549 cells (peak L-type Ca 2+ current (I CaL ) at 0 mV: α 1c-wt −9.94 ± 1.00 pA/pF, n = 9; α 1c-D-−10.30 pA/pF, n = 12). I CaL carried by α 1c-D-was markedly less sensitive to nitrendipine (IC 50 17.1 µM) than α 1c-wt (IC 50 88 nM); a feature exploited to discriminate between engineered and native currents in transduced guinea-pig myocytes. 10 µM nitrendipine blocked only 51 ± 5% (n = 9) of I CaL in α 1c-D--expressing myocytes, in comparison to 86 ± 8% (n = 9) of I CaL in control myocytes. Moreover, in 20 µM nitrendipine, calcium transients could still be evoked in α 1c-D--transduced cells, but were largely blocked in control myocytes, indicating that the engineered channels were coupled to sarcoplasmic reticular Ca 2+ release. These α 1c adenoviruses provide an unprecedented tool for structure-function studies of cardiac excitationcontraction coupling and L-type Ca 2+ channel regulation in the native myocyte background. KeywordsDihydropyridine; Excitation-contraction coupling; Gene transfer; Adenovirus; Ion channelThe cardiac L-type Ca 2+ channel (Ca v 1.2a) is a multisubunit complex of five proteins located on the surface membrane of the cardiac myocyte. The largest component is the pore-forming α 1 subunit (∼220 kDa), the critical determinant of most functional properties of the channel, including voltage-dependent gating, Ca 2+ permeability, Ca 2+ -dependent inactivation [1,2], and inhibition by the three principal classes of Ca 2+ channel antagonists [3][4][5].

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“…The transmembrane segments S5 and S6 of repeat III and the transmembrane segment S6 of repeat IV have been assigned to the interaction sites of L-type Ca 2 þ channels with DHP (Hockerman et al, 1997;Hering et al, 1998;Striessnig et al, 1998). In these regions of Ca 2 þ channels, amino-acid sequences of T-type a 1G , a1H and a 1I channels are the most diverse compared to those of L-type a 1C , a 1S and a 1D channels among the voltage-dependent Ca 2 þ channels known (PerezReyes, 2003a).…”

Section: T Furukawa Et Almentioning

confidence: 99%

Identification of R(−)‐isomer of efonidipine as a selective blocker of T‐type Ca²⁺ channels

Furukawa

Miura

Honda

et al. 2004

British J Pharmacology

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1 Efonidipine, a derivative of dihydropyridine Ca 2 þ antagonist, is known to block both L-and T-type Ca 2 þ channels. It remains to be clarified, however, whether efonidipine affects other voltagedependent Ca 2 þ channel subtypes such as N-, P/Q-and R-types, and whether the optical isomers of efonidipine have different selectivities in blocking these Ca 2 þ channels, including L-and T-types. 2 To address these issues, the effects of efonidipine and its R(À)-and S( þ )-isomers on these Ca 2 þ channel subtypes were examined electrophysiologically in the expression systems using Xenopus oocytes and baby hamster kidney cells (BHK tk-ts13). 3 Efonidipine, a mixture of R(À)-and S( þ )-isomers, exerted blocking actions on L-and T-types, but no effects on N-, P/Q-and R-type Ca 2 þ channels. 4 The selective blocking actions on L-and T-type channels were reproduced by the S( þ )-efonidipine isomer. 5 By contrast, the R(À)-efonidipine isomer preferentially blocked T-type channels. 6 The blocking actions of efonidipine and its enantiomers were dependent on holding potentials. 7 These findings indicate that the R(À)-isomer of efonidipine is a specific blocker of the T-type Ca 2 þ channel.

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Structural basis of drug binding to L Ca2+ channels

Cited by 252 publications

References 39 publications

Functional Embryonic Cardiomyocytes after Disruption of the L-type α1C (Ca 1.2) Calcium Channel Gene in the Mouse

Functional Embryonic Cardiomyocytes after Disruption of the L-type α1C (Ca 1.2) Calcium Channel Gene in the Mouse

Reverse engineering the L-type Ca2+ channel α1c subunit in adult cardiac myocytes using novel adenoviral vectors

Identification of R(−)‐isomer of efonidipine as a selective blocker of T‐type Ca²⁺ channels

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Structural basis of drug binding to L Ca2+ channels

Cited by 252 publications

References 39 publications

Functional Embryonic Cardiomyocytes after Disruption of the L-type α1C (Ca 1.2) Calcium Channel Gene in the Mouse

Functional Embryonic Cardiomyocytes after Disruption of the L-type α1C (Ca 1.2) Calcium Channel Gene in the Mouse

Reverse engineering the L-type Ca2+ channel α1c subunit in adult cardiac myocytes using novel adenoviral vectors

Identification of R(−)‐isomer of efonidipine as a selective blocker of T‐type Ca2+ channels

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Identification of R(−)‐isomer of efonidipine as a selective blocker of T‐type Ca²⁺ channels