Aplip1, a potential scaffold protein of Drosophila melanogaster, may be involved in facilitating signal transduction
The mammalian JIP group of proteins have been shown to have a physiologically important role in controlling the specificity of JNK signal transduction. The Drosophila gene SP512 has been identified as a homologue of JIP1 and JIP2, and is termed aplip1. Expression studies of the aplip1 gene reveal that it is expressed in the embryonic nervous system, the eye imaginal disc, and the nurse cells of the developing oocyte. In an attempt to generate an alpha-Aplip1 antibody, 6xHIS-tagged Aplip1 protein was expressed in E. coli and purified on a Ni2+-NTA column. The resulting purified Aplip1 protein used to generate an antibody that bound to the protein in vitro but did not when the protein was present in physiological levels. To investigate the function of aplip1 in Drosophila the protein was used in the yeast two-hybrid assay to show that it could interact with the products of the basket, rolled, jun-related antigen, and kinesin light chain genes. Partial deletions of the Aplip1 protein were used to refine the areas of the protein with which these partners could interact, showing that they all interact with the N-terminal region. Finally RNA interference was used to reduce the levels of aplip1, although no mutant phenotype could be detected.