komplexinen

Komplexinen are a family of small presynaptic proteins that regulate neurotransmitter release by interacting with the SNARE complex, the core machinery that drives vesicle fusion at chemical synapses. The term is used in various languages; in English literature the protein is commonly called complexin, with multiple isoforms described. Komplexinen function as regulators that influence when and how readily synaptic vesicles fuse with the presynaptic membrane in response to calcium signals.

In mammals, four genes encode komp läx? No, CPLX1–CPLX4, giving rise to Complexin-1 through Complexin-4 isoforms. These proteins are typified by a conserved central helix that binds to the partially assembled SNARE complex, while their flexible N- and C-terminal regions contribute to isoform-specific regulation and localization. The overall size is small, and the proteins are soluble within the cytoplasm of presynaptic terminals.

Functionally, komplexinen act as clamps that prevent premature fusion and stabilize SNARE complexes until calcium influx triggers rapid release. Upon Ca2+ entry, interactions with other exocytosis factors, such as synaptotagmin, promote timely fusion and transmitter release. Isoforms show distinct expression patterns: some are enriched in certain brain regions or synapse types, implying specialized roles in synchronous versus asynchronous release and short-term plasticity.

Localization is predominantly presynaptic, at active zones of terminals, and kom-p Lexin sequences are conserved across vertebrates, reflecting essential cellular roles. Disruption of komplexinen in model systems impairs synaptic transmission and alters plasticity, underscoring their importance for proper nervous system function. Some studies explore links to neurodevelopmental and neuropsychiatric conditions, though redundancy among isoforms often modulates phenotypic outcomes.