Regenerative · Cell-penetrating connexin 43-derived interaction peptide
Alpha-connexin carboxyl-terminal peptide 1 (alphaCT1)
Also known as αCT1; aCT1; ACT1
A cell-penetrating connexin 43 tail mimetic used to study scaffold binding, gap-junction organisation and tissue remodelling.
- Length
- 25 amino acids
- Half-life
- Not well characterised
- Mechanism
- alphaCT1 contains the connexin 43 C-terminal PDZ-binding motif, enabling interaction with the PDZ2 domain of zonula occludens-1 and modulation of connexin 43–scaffold associations. Effects on connexin 43 phosphorylation and channel organisation have also been reported; it is not a conventional receptor agonist.
- Studied in
- Cell monolayers, gap-junction imaging assays and animal tissue-injury models investigate connexin organisation, intercellular coupling and remodelling-associated signalling.
About Alpha-connexin carboxyl-terminal peptide 1 (alphaCT1)
alphaCT1 combines a 16-residue antennapedia-derived cell-penetrating segment with the final nine amino acids of connexin 43, RPRPDDLEI. Connexin 43, encoded by GJA1, forms channels that support communication between neighbouring cells. Its cytoplasmic tail also binds regulatory proteins. The peptide was developed from studies of this tail's interaction with zonula occludens-1, a scaffold linking junctional proteins to broader cellular organisation rather than a membrane receptor.
The terminal DLEI motif engages the second PDZ domain of zonula occludens-1, making preservation of the peptide's free C-terminal carboxyl group important. Experimental studies examine changes in connexin 43 distribution, junctional plaque organisation and hemichannel-associated activity. Additional work implicates connexin 43 tail interactions and phosphorylation, including serine 368. These overlapping mechanisms mean that a cellular response cannot automatically be assigned solely to disruption of scaffold binding.
Laboratory notes
- Confirm the complete fusion sequence and free C-terminal carboxyl group; C-terminal labelling or amidation may disrupt PDZ-domain recognition.
- Include a cell-penetrating-segment control to distinguish cargo-dependent effects from effects of the delivery sequence.
- Measure cell viability alongside junctional coupling and hemichannel readouts, and document connexin 43 and zonula occludens-1 expression.
Storage and reconstitution basics: storage guide.
Questions about Alpha-connexin carboxyl-terminal peptide 1 (alphaCT1)
Which part comes from connexin 43?
The final nine residues, RPRPDDLEI, reproduce the connexin 43 C-terminal segment; the preceding segment supports cellular uptake in experimental systems.
Does alphaCT1 target a cell-surface receptor?
Its best-characterised interactions involve intracellular protein domains, notably the PDZ2 domain of zonula occludens-1, rather than a conventional cell-surface receptor.
Why is terminal chemistry important?
PDZ recognition commonly depends on a free terminal carboxyl group. Research-use variants with C-terminal modifications require separate binding and functional validation.
Is Alpha-connexin carboxyl-terminal peptide 1 (alphaCT1) for human use?
No. It is supplied strictly for in-vitro laboratory research and is not for human or animal consumption.
Related research peptides
All products are sold for laboratory research use only. Not for human consumption, not a medicine, not for diagnosing, treating or preventing any condition.