Meeting Abstract

29.4  Saturday, Jan. 4 14:15  Phenolog approach identifies a novel gene that interacts with sodium leak channels (NALCN) and affects Drosophila behaviour. LIEBESKIND, BJ*; GHEZZI, A; HILLIS, DM; ATKINSON, NS; ZAKON, HH; Univ. of Texas at Austin; Univ. of Texas at Austin; Univ. of Texas at Austin; Univ. of Texas at Austin; Univ. of Texas at Austin bliebeskind@austin.utexas.edu

Behavioral plasticity in animals often depends on subtle changes in the intrinsic excitability of a subset of neurons. Small changes in membrane permeability that affect the resting potential can alter intrinsic excitability, and sodium leak channels (NALCN) have recently been implicated in this mechanism and in rhythmic behaviors in a variety of species. The full complexity of NALCN function is only just beginning to be appreciated, however. It is now known that NALCN channels can associate with numerous subunits in different tissues and can be activated, via poorly understood mechanisms, by several different peptides and second messengers. We show that NALCN channels are closely related to fungal calcium channels, which they functionally resemble. We then use this relationship to suggest an association between NALCN and a previously undescribed protein in Drosophila on the basis of homology with the yeast protein Mid1, the subunit of the yeast calcium channel. This novel gene is co-ordinately expressed with NALCN, and knockdown of either gene creates identical phenotypes in several behaviors associated with NALCN function. We therefore suggest a genetic association between this novel gene and NALCN in Drosophila. The conservation of this association between flies and fungi suggest that yeast can be a useful model for NALCN function in animals.