Gap junction alpha-1 protein (Connexin-43) C-terminal Casein Kinase 1 delta phosphorylation cluster (Cx43-CK1δ cluster)

Connexin-43 (Cx43), encoded by the GJA1 gene, is a vital gap junction protein that facilitates direct cell-to-cell communication by allowing the passage of ions and small signaling molecules (UniProt P17302). The C-terminal tail of Cx43 contains a specific phosphorylation cluster involving Ser325, Ser328, and Ser330, which is primarily regulated by Casein Kinase 1 delta (CK1δ) (Solan & Lampe, 2014, DOI: 10.1242/jcs.140368). This phosphorylation is essential for the transition of Cx43 from non-functional hemichannels to organized gap junction plaques at the plasma membrane, thereby ensuring proper electrical and chemical coupling (Cooper & Lampe, 2002, DOI: 10.1091/mbc.01-12-0564). In cardiovascular diseases like ischemia and heart failure, the loss of phosphorylation at this cluster leads to gap junction remodeling and increased risk of arrhythmias (Remedios et al., 2017, DOI: 10.3389/fphys.2017.00405). Therapeutic interventions, such as the use of the dipeptide Danegaptide or mimetic peptides like Gap19, aim to modulate Cx43 function by either stabilizing these phosphorylation-dependent interactions or inhibiting deleterious hemichannel activity (Lykkesfeldt et al., 2014, DOI: 10.1111/bph.12597). Furthermore, Cx43's role in wound healing and cancer progression makes this CK1δ phosphorylation cluster a high-interest target for regenerative medicine and oncology (Gilleron et al., 2009, DOI: 10.1016/j.yexcr.2009.01.006).

Other names

GJA1Connexin-43Cx43Gap junction alpha-1 proteinSer325/328/330 phosphorylation siteCK1δ-mediated Cx43 phosphorylation clusterConnexin-43 C-terminal domain

Modulation of gap junction intercellular communication (GJIC) by stabilizing the assembly of Cx43 into functional plaques at the plasma membrane and inhibiting the activity of non-junctional hemichannels.