Protein / target

Voltage-dependent P/Q-type calcium channel subunit alpha-1A

CACNA1AO00555Homo sapiensSwiss-Prot
Clinically validated
Therapeutic maturity
7
Approved medicines
30
Clinical trials
Small-molecule tractable
Druggability
Approved Drug

Protein at a glance

Biological role

High voltage-gated calcium channel activity

Primary system

Nervous system

Strongest disease association

episodic ataxia type 2

Genetic evidence · score 0.97

Therapeutic maturity

Clinically validated target

7 approved medicines against this target

Druggability

Small molecule

Open Targets tractability · Approved Drug

Clinical development

7 approved · 3 in clinical development

30 linked trials

Derived from structured UniProt, Open Targets and literature data on this page.

Protein profile

UniProt 2026_02

Canonical identity and biological annotation from UniProt.

Function

Voltage-sensitive calcium channels (VSCC) mediate the entry of calcium ions into excitable cells and are also involved in a variety of calcium-dependent processes, including muscle contraction, hormone or neurotransmitter release, gene expression, cell motility, cell division and cell death. The isoform alpha-1A gives rise to P and/or Q-type calcium currents. P/Q-type calcium channels belong to the 'high-voltage activated' (HVA) group and are specifically blocked by the spider omega-agatoxin-IVA (AC P54282) (By similarity). They are however insensitive to dihydropyridines (DHP)

Subcellular location

Cell membrane
Domains and Gene Ontology detail (20)

Gene Ontology

  • Ccell projection
  • Ccytoplasm
  • Cmembrane
  • Cneuronal cell body
  • Cnucleus
  • Cplasma membrane
  • Csynapse
  • Cvoltage-gated calcium channel complex
  • Famyloid-beta binding
  • Fhigh voltage-gated calcium channel activity
  • Fmetal ion binding
  • Fsyntaxin binding

2506 aa · 283 kDa · 6 isoforms

Biological roles

Reactome v97

What this protein does, drawn together from its UniProt function, Gene Ontology terms and Reactome pathways.

Synaptic signallingGO · ReactomeIon channel gatingGOTranscriptional regulationUniProtMuscle contractionUniProt
View supporting evidence

Synaptic signalling

  • ·synapse
  • ·chemical synaptic transmission
  • ·modulation of chemical synaptic transmission
  • ·Presynaptic depolarization and calcium channel opening

Ion channel gating

  • ·calcium ion transmembrane transport

Transcriptional regulation

  • ·Voltage-sensitive calcium channels (VSCC) mediate the entry of calcium ions into excitab…

Muscle contraction

  • ·Voltage-sensitive calcium channels (VSCC) mediate the entry of calcium ions into excitab…
View underlying pathways (2)

Concepts derived from UniProt GO Reactome — each badge above shows which sources supported that role.

Interaction neighbourhood

STRING v12.0

Proteins with the strongest functional or physical association. Node size and line weight reflect STRING confidence; hover or select a partner to inspect one association.

CACNB4CACNA2…PRKCGCALM3ATXN7-2ATXN7CACNB2CACNA1CCACNA2…CACNA1ECACNA1A

10 strongest partners — larger node and heavier line mean higher confidence

Functional and physical associations from STRING v12.0. Only associations with this protein are drawn — partner-to-partner links are not part of this evidence.

Drugs targeting this protein

1

Whether each drug engages this protein directly or through a complex, and how many other targets are recorded for it. Direct binders with few recorded targets are listed first.

gabapentin
ApprovedModulator

Voltage-gated calcium channel modulator

Appears in clinical studies involving Seizure, epilepsy, Focal-onset seizure, restless legs syndrome

Acts on a complex — shared with CACNB4, CACNG4, CACNG3 +22 more · 1 of 26 recorded protein targets — broad pharmacology

ChEMBL mechanism, action type and target identity. Open Targets clinical status and indications.

Translational evidence

Open Targets 26

Why this target matters therapeutically — disease associations, drugs in development, tractability and safety, from Open Targets.

Strongest genetic associations

Human genetic evidence — the most direct causal link between this target and a disease.

episodic ataxia type 20.97

Genetic · overall 0.83

migraine, familial hemiplegic, 10.96

Genetic · overall 0.82

developmental and epileptic encephalopathy, 420.93

Genetic · overall 0.81

Familial paroxysmal ataxia0.91

Genetic · overall 0.83

spinocerebellar ataxia type 60.90

Genetic · overall 0.77

Highest-confidence therapeutic associations

Diseases where a drug acting on this target has already reached clinical development.

epilepsy1.00

Clinical · overall 0.64

neuropathic pain0.99

Clinical · overall 0.60

fibromyalgia0.99

Clinical · overall 0.60

Seizure0.99

Clinical · overall 0.72

Highest overall evidence

Remaining associations by Open Targets' aggregated evidence score.

familial or sporadic hemiplegic migraine0.68

Genetic literature

Show all associations
Familial paroxysmal ataxia0.83
episodic ataxia type 20.83
migraine, familial hemiplegic, 10.82
developmental and epileptic encephalopathy, 420.81
spinocerebellar ataxia type 60.77
Seizure0.72
familial or sporadic hemiplegic migraine0.68
epilepsy0.64
neuropathic pain0.60
fibromyalgia0.60

Open Targets ranks 2,717 associations for this target and we store the top 10 by aggregated score. The long tail is largely literature co-mention and RNA-expression evidence, not evidence that this target drives those diseases.

Known drugs · 11 total

GABAPENTINApproval

Seizure · epilepsy · Focal-onset seizure

BEPRIDILApproval

cardiovascular disorder

SULOCTIDILApproval

cardiovascular disorder

ELPETRIGINEPhase 1

bipolar disorder

PHLOROGLUCINOLApproval

gastrointestinal disease · urinary system disorder · renal colic

ATAGABALINPhase 2

insomnia

TERODILINEApproval

Polyuria · Urinary incontinence

TERODILINE HYDROCHLORIDEUnknown
GABAPENTIN ENACARBILApproval

restless legs syndrome · neuralgia · Sleep disturbance

IMAGABALINPhase 3

generalized anxiety disorder

Tractability

SM · Approved DrugSM · Structure with LigandSM · High-Quality LigandSM · Druggable FamilyAB · UniProt loc high confAB · GO CC high confAB · UniProt SigP or TMHMMPR · Database UbiquitinationPR · Small Molecule Binder

Clinical trials

30

Trials of drugs that target this protein — reached indirectly through those drugs, so a trial listed here studies the drug, not the protein.

Show remaining trials (24)

COMPLETED · via gabapentin · NCT02330094

COMPLETED · via gabapentin · NCT00279487

COMPLETED · via gabapentin · NCT00058890

RECRUITING · via gabapentin · NCT04724252

COMPLETED · via gabapentin · NCT00218374

UNKNOWN · via gabapentin · NCT00209872

ClinicalTrials.gov via the drug-target graph.

Forefront confidence

Synthesis

Our own weighting of the evidence behind each disease association. Human genetics and clinical evidence count for most; literature co-mention counts for little, because two entities sharing an abstract is not evidence that one drives the other.

episodic ataxia type 2Well supported
0.98
agreement 0.861.00
Genetic77%Animal model19%Literature4%Genetic literaturedup

Open Targets aggregate 0.83 · 3 independent evidence families · 1 not counted as duplicate

migraine, familial hemiplegic, 1Well supported
0.97
agreement 0.851.00
Genetic77%Animal model22%Literature1%Genetic literaturedup

Open Targets aggregate 0.82 · 3 independent evidence families · 1 not counted as duplicate

developmental and epileptic encephalopathy, 42Well supported
0.95
agreement 0.831.00
Genetic79%Animal model20%Literature0%Genetic literaturedup

Open Targets aggregate 0.81 · 3 independent evidence families · 1 not counted as duplicate

SeizureWell supported
0.94
agreement 0.831.00
Genetic51%Clinical49%Literature1%

Open Targets aggregate 0.72 · 3 independent evidence families

Familial paroxysmal ataxiaWell supported
0.93
agreement 0.811.00
Genetic75%Animal model21%Literature4%Genetic literaturedup

Open Targets aggregate 0.83 · 3 independent evidence families · 1 not counted as duplicate

This ranking differs from Open Targets' own: re-weighting moves genetically-evidenced diseases above more heavily co-mentioned ones. The evidence agreement range shows how closely the independent evidence families agree — it is not a statistical confidence interval, and nothing here is fitted to outcome data. Derived from Open Targets evidence types under Forefront weighting; the underlying per-type scores are shown above so the calculation can be checked.

What's happening now

30

Recent activity around this target, drawn from one canonical event stream. Every item is reached through a drug that targets this protein, so each event is news about that drug rather than about the protein directly.

  1. Label change2026-07-22

    Label change: GABAPENTIN (ANDA217995)

    fda · regulatory · fda · via gabapentin

  2. Label change2026-07-17

    Label change: GABAPENTIN (ANDA203934)

    fda · regulatory · fda · via gabapentin

  3. Label change2026-07-16

    Label change: GABAPENTIN (ANDA075428)

    fda · regulatory · fda · via gabapentin

  4. Label change2026-06-25

    Label change: GABAPENTIN (ANDA077661)

    fda · regulatory · fda · via gabapentin

  5. Regulatory approval2026-06-23

    Approval: GABAPENTIN (ANDA203611)

    fda · regulatory · fda · via gabapentin

  6. Label change2024-12-27

    Label change: GABAPENTIN (ANDA217995)

    fda · regulatory · fda · via gabapentin

  7. Label change2024-12-16

    Label change: GABAPENTIN (ANDA075428)

    fda · regulatory · fda · via gabapentin

  8. Label change2024-07-08

    Label change: GABAPENTIN (ANDA075428)

    fda · regulatory · fda · via gabapentin

  9. Label change2024-07-08

    Label change: GABAPENTIN (ANDA075428)

    fda · regulatory · fda · via gabapentin

  10. Regulatory approval2024-01-24

    Approval: GABAPENTIN (ANDA203934)

    fda · regulatory · fda · via gabapentin

  11. Label change2023-09-21

    Label change: GABAPENTIN (ANDA077661)

    fda · regulatory · fda · via gabapentin

  12. Label change2023-09-21

    Label change: GABAPENTIN (ANDA077661)

    fda · regulatory · fda · via gabapentin

Objective event titles are shown unmodified; the event kind and significance line are derived from structured fields. Forefront AttentionEvent stream aggregating Europe PMC Regulatory filings ClinicalTrials.gov.