Characterization of big bang, a novel Drosophila gene encoding PDZ domain-containing proteins involved in locomotor behaviour.
Published: 2006
Language: eng
Number of pages: 181
ISBN-13: 9780494219348
Description: PDZ (PSD-95, Discs-large,  ZO-1) domain proteins often function as scaffolding proteins and have been shown to play important roles in diverse cellular processes such as the establishment and maintenance of cell polarity, and signal transduction. Here, I describe the cloning and characterization of a novel Drosophila melanogaster gene that was first identified as C96-GAL4, a GAL4 enhancer trap line. C96, renamed big bang (bbg), is a large and complex gene predicted to produce several different PDZ domain-containing proteins through alternative promoter usage and alternative splicing. Using UAS reporter gene constructs, in situ hybridization, and immunocytochemistry, the expression patterns of bbg were examined throughout development. bbg is expressed in developing embryos, third instar larvae, and in adults, in a wide variety of cell types and tissues, including the gut, muscle, and nervous system. To determine the function of bbg, several different bbg mutations were generated and identified. These mutations are recessive and strongly hypomorphic, or possibly null. bbg mutant adults are not defective in locomotion per se, but appear to have an abnormal response to mechanical shock, i.e. they appear to be mildly bang-sensitive. To identify proteins that may interact with the products of  bbg (BBG), and thus gain further insight into their function, yeast two-hybrid screens were carried out using two PDZ domains found in common to all bbg proteins. Preliminary results from this screen suggest that the most C-terminal PDZ domain of BBG interacts with the Na +/K+ ATPase, also known as the sodium pump alpha subunit (ATPalpha), encoded by the Atpalpha gene. Interestingly,  Atpalpha mutant adults are also mildly bang-sensitive. Thus, BBG and ATPalpha may interact in vivo, which would be the first example of a specific and direct functional relationship between products of two genes involved in bang-sensitivity. Since bbg encodes multiple PDZ domain-containing proteins, and is broadly and dynamically expressed throughout development, bbg is very likely pleiotropic in function. Thus, in addition to its role in adult locomotor behaviour,  bbg may play other important roles in development.
Notes: Source: Dissertation Abstracts International, Volume: 68-01, Section: B, page: 0063.

Thesis (Ph.D.)--University of Toronto, 2006.

Electronic version licensed for access by U. of T. users.