ABSTRACT
Connexin hemichannels are important in the normal cell physiology and in the pathophysiology of frequent disorders, and therefore understanding their basic properties and regulation is essential to explain normal and abnormal processes. This chapter focuses on connexin 26 (Cx26) and Cx43 as models for studies of purified connexin hemichannels because of their medical importance and because these two isoforms are distinct in terms of their amino acid sequence and length of the C-terminal region. For biochemical and structural studies that require larger amounts of purified connexins, insect cells have been the preferred choice. The chapter presents examples of the use of purified hemichannels to address the molecular mechanism of the regulation of Cx43 hemichannels by protein kinase C (PKC)-mediated phosphorylation. The methodologies for hemichannel expression/purification and the functional and structural analyses of connexin hemichannels are still underdeveloped.
