Role of a conserved glutamine in the function of voltage-gated Ca 2+ channels revealed by a mutation in human CACNA1D

Edgar Garza-Lopez; Josue A Lopez; Jussara Hagen; Ruth Sheffer; Vardiella Meiner; Amy Lee

doi:10.1074/jbc.RA118.003681

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Role of a conserved glutamine in the function of voltage-gated Ca 2+ channels revealed by a mutation in human CACNA1D

Journal article

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Role of a conserved glutamine in the function of voltage-gated Ca 2+ channels revealed by a mutation in human CACNA1D

Edgar Garza-Lopez, Josue A Lopez, Jussara Hagen, Ruth Sheffer, Vardiella Meiner and Amy Lee

The Journal of biological chemistry, Vol.293(37), pp.14444-14454

09/14/2018

DOI: 10.1074/jbc.RA118.003681

PMCID: PMC6139563

PMID: 30054272

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Abstract

Voltage-gated Ca Ca channels play crucial roles in regulating gene transcription, neuronal excitability, and synaptic transmission. Natural or pathological variations in Ca channels have yielded rich insights into the molecular determinants controlling channel function. Here, we report the consequences of a natural, putatively disease-associated mutation in the gene encoding the pore-forming Ca 1.3 α subunit. The mutation causes a substitution of a glutamine residue that is highly conserved in the extracellular S1-S2 loop of domain II in all Ca channels with a histidine and was identified by whole-exome sequencing of an individual with moderate hearing impairment, developmental delay, and epilepsy. When introduced into the rat Ca 1.3 cDNA, Q558H significantly decreased the density of Ca currents in transfected HEK293T cells. Gating current analyses and cell-surface biotinylation experiments suggested that the smaller current amplitudes caused by Q558H were because of decreased numbers of functional Ca 1.3 channels at the cell surface. The substitution also produced more sustained Ca currents by weakening voltage-dependent inactivation. When inserted into the corresponding locus of Ca 2.1, the substitution had similar effects as in Ca 1.3. However, the substitution introduced in Ca 3.1 reduced current density, but had no effects on voltage-dependent inactivation. Our results reveal a critical extracellular determinant of current density for all Ca family members and of voltage-dependent inactivation of Ca 1.3 and Ca 2.1 channels.

Mutation

Amino Acid Sequence

Synaptic Transmission - physiology

Calcium Signaling - physiology

Glutamine - physiology

Humans

Calcium Channels, L-Type - physiology

Intellectual Disability - genetics

Whole Exome Sequencing

Hearing Loss - genetics

Sequence Homology, Amino Acid

Ion Channel Gating - physiology

Calcium Channels, L-Type - genetics

Glycine - chemistry

Conserved Sequence

Histidine - chemistry

Calcium Channels, L-Type - chemistry

Details

Title: Subtitle: Role of a conserved glutamine in the function of voltage-gated Ca 2+ channels revealed by a mutation in human CACNA1D
Creators: Edgar Garza-Lopez - From the Departments of Molecular Physiology and Biophysics, Otolaryngology Head-Neck Surgery, and Neurology and Iowa Neuroscience Institute, University of Iowa, Iowa City, Iowa 52242 and
Josue A Lopez - From the Departments of Molecular Physiology and Biophysics, Otolaryngology Head-Neck Surgery, and Neurology and Iowa Neuroscience Institute, University of Iowa, Iowa City, Iowa 52242 and
Jussara Hagen - From the Departments of Molecular Physiology and Biophysics, Otolaryngology Head-Neck Surgery, and Neurology and Iowa Neuroscience Institute, University of Iowa, Iowa City, Iowa 52242 and
Ruth Sheffer - Department of Genetics and Metabolic Diseases, Hadassah-Hebrew University Medical Center, Jerusalem 91120, Israel
Vardiella Meiner - Department of Genetics and Metabolic Diseases, Hadassah-Hebrew University Medical Center, Jerusalem 91120, Israel
Amy Lee - From the Departments of Molecular Physiology and Biophysics, Otolaryngology Head-Neck Surgery, and Neurology and Iowa Neuroscience Institute, University of Iowa, Iowa City, Iowa 52242 and amy-lee@uiowa.edu
Resource Type: Journal article
Publication Details: The Journal of biological chemistry, Vol.293(37), pp.14444-14454
DOI: 10.1074/jbc.RA118.003681
PMID: 30054272
PMCID: PMC6139563
NLM abbreviation: J Biol Chem
ISSN: 0021-9258
eISSN: 1083-351X
Publisher: United States
Grant note: R01 NS084190 / NINDS NIH HHS R01 DC009433 / NIDCD NIH HHS R55 DC009433 / NIDCD NIH HHS
Language: English
Date published: 09/14/2018
Academic Unit: Molecular Physiology and Biophysics
Record Identifier: 9984071793602771

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