The gap junction cellular internet: connexin hemichannels enter the signalling limelight

Area of Science:

• Cellular Biology
• Biophysics
• Molecular Medicine

Background:

• Connexins (Cxs) form gap junction channels for direct cell-to-cell communication.
• Connexin hemichannels (CxHcs) are precursors to gap junctions, releasing paracrine messengers.
• CxHcs respond to diverse cellular stresses and intracellular signals, including calcium.

Purpose of the Study:

• To elucidate the distinct roles of CxHcs in cellular physiology and pathology.
• To investigate the involvement of CxHcs in intercellular signaling and calcium homeostasis.
• To explore the utility of synthetic peptides in differentiating CxHc and gap junction functions.

Main Methods:

• Analysis of CxHc function in response to various physiological and pathological stimuli.
• Investigation of CxHc interaction with intracellular calcium signaling pathways.
• Utilizing synthetic peptides mimicking connexin sequences to probe CxHc activity.

Main Results:

• CxHcs release key signaling molecules like ATP and glutamate, mediating paracrine communication.
• CxHcs are activated by physiological calcium levels and significantly influence cellular calcium homeostasis.
• Synthetic peptides show promise in dissecting the specific contributions of CxHcs.

Conclusions:

• CxHcs play crucial roles in intercellular communication and calcium signaling beyond their role as gap junction precursors.
• CxHc activity is modulated by both external stresses and intracellular signals, including physiological calcium.
• Targeted peptide inhibitors offer a valuable approach to understanding CxHc functions in health and disease.