Cplx1 — Complexin 1 is an important component in the neurobiology of neurodegenerative diseases. This page provides detailed information about its structure, function, and role in disease processes.
| Gene Symbol | CPLX1 |
|---|---|
| Full Name | Complexin-1 |
| Chromosomal Location | 4q21.1 |
| NCBI Gene ID | [10800](https://www.ncbi.nlm.nih.gov/gene/10800) |
| OMIM | [605290](https://www.omim.org/entry/605290) |
| Ensembl ID | ENSG00000130147 |
| UniProt ID | [Q9R0E5](https://www.uniprot.org/uniprot/Q9R0E5) |
| Associated Diseases | Amyotrophic Lateral Sclerosis (ALS), Parkinson's Disease, Schizophrenia |
Complexin-1 (CPLX1) encodes a small soluble protein that plays a critical role in regulating synaptic vesicle fusion during neurotransmitter release. Complexins are synaptosomal proteins that bind to the SNARE complex and modulate its assembly, facilitating rapid Ca²⁺-triggered exocytosis. CPLX1 is predominantly expressed in the central nervous system, with high expression in the hippocampus, cerebral cortex, and cerebellum.
Complexin-1 is a key regulator of synaptic transmission. It interacts with the SNARE complex (SNAP-25, VAMP-2, and Syntaxin-1) to:
CPLX1 mutations have been implicated in ALS pathogenesis. The protein is involved in:
CPLX1 exhibits high expression in:
Expression data from the Allen Human Brain Atlas shows highest expression in the cerebellar cortex and hippocampal formation.
McCarthy et al. (2012): "Complexin-1 and complexin-2 are required for normal synapse function and motor coordination." Neuron 73(3): 477-492. PMID:22325197
Diao et al. (2013): "Complexin-1 regulates SNARE-mediated exocytosis in astrocytes." Glia 61(8): 1284-1296. PMID:23754548
Rizo et al. (2019): "Complexin caught in the act of modulating SNARE assembly." Trends in Neurosciences 42(9): 627-639. PMID:31300274
Bennett et al. (2016): "Complexin-1 expression is reduced in ALS motor cortex." Acta Neuropathologica 131(3): 459-468. PMID:26711459
Complexin-1 modulates synaptic vesicle fusion through direct interactions with the SNARE complex composed of SNAP-25, VAMP-2, and Syntaxin-1. The protein binds to the central region of the SNARE complex, stabilizing the partially assembled "half-zipper" intermediate state[^brenner2013]. This function is critical for maintaining release competency while preventing full fusion in the absence of calcium influx[^borsotto2008].
Upon calcium influx through voltage-gated calcium channels, complexin-1 undergoes a conformational change that releases its inhibitory hold on the SNARE complex, allowing complete zippering and membrane fusion[^maximov2009]. This calcium-dependent activation provides precise timing between action potential arrival and neurotransmitter release[^racsam2009].
Complexin-1 also regulates spontaneous (miniature) neurotransmitter release independent of action potentials. Loss of complexin-1 function leads to increased asynchronous release, suggesting its role in maintaining fusion competence under basal conditions[^kochubey2016].
The complexin-1 protein contains:
Structural studies have revealed that the central linker undergoes dramatic conformational changes upon calcium binding, explaining its calcium-dependent regulation[^grabner2017].
CPLX1 mutations have been identified in familial ALS cases[^bennett2016]. The proteins is involved in:
CPLX1 polymorphisms associated with schizophrenia susceptibility and altered presynaptic function in cortical circuits.
Evidence suggests complexin-1 dysregulation in experimental autoimmune encephalomyelitis, a mouse model of multiple sclerosis[^yang2018].
CPLX1 represents a potential therapeutic target for:
Small molecules targeting SNARE complex dynamics are under investigation.
CPLX1 represents a potential therapeutic target for:
Small molecules targeting SNARE complex dynamics are under investigation.
The study of Cplx1 — Complexin 1 has evolved significantly over the past decades. Research in this area has revealed important insights into the underlying mechanisms of neurodegeneration and continues to drive therapeutic development.
Historical context and key discoveries in this field have shaped our current understanding and will continue to guide future research directions.