Chapter 16: Gating of Gap Junction Channels and Hemichannels in the Lens: A Role in Cataract?

Abstract

Publisher Summary The ocular lens, because of its syncytial properties, has traditionally attracted researchers interested in the structure and function of gap junctions. Such intense research activity has produced a wealth of information on the ultrastructure and localization of gap junction plaques in the lens, their formation as a function of cellular differentiation, the identification of the connexin isoforms that form the lens gap junction channels, the age-related cleavage that is so far unique to lens connexins, and the functional properties of the lens gap junction channels. The importance of gap junction channels for lens development and homeostasis has been highlighted by the finding that genetic disruption of or mutation to the lens connexins causes severe cell damage and cataract. This chapter focuses on observations that characterize the role gap junction channels play in lens homeostasis. In particular, recent evidence on the gating properties of the gap junction channels and the discovery of putative gap junction hemichannels are reviewed and discussed in terms of their relevance for the maintenance of lens transparency.