Electronic Thesis and Dissertation Repository


Master of Science


Physiology and Pharmacology


Bai, Donglin


Gap junction (GJ) channels provide direct intercellular communication. A GJ channel consists of two docked hemichannels and each hemichannel is a hexamer of six connexins. Human vascular connexins (Cx37, Cx40, Cx43, and Cx45) can form various types of gap junction channels to synchronize vasodilation/constriction to control local circulation. Most of our knowledge on heterotypic GJs of these vascular connexins comes from studies on rodent connexins. However it is not clear if these human connexins can also form heterotypic GJs. The present study used an in vitro expression system to investigate the coupling status and GJ properties of human heterotypic Cx37/Cx40, Cx37/Cx43, and Cx37/Cx45 GJs. Our results showed that Cx37/Cx43 and Cx37/Cx45 GJs, but not Cx37/Cx40 GJs, were functional and with unique rectifying channel properties. The docking between Cx37 and Cx40 could be rescued by designed Cx40 variants. The unique heterotypic Cx37/Cx43 and Cx37/Cx45 GJ properties may help us understand the intercellular communication between vascular cells.