Genetics. Published Articles Ahead of Print: December 18, 2006, Copyright © 2006
doi:10.1534/genetics.106.067959


A more recent version of this article appeared on March 1, 2007.

REGULAR RESEARCH PAPERS

Identification of genes that interact with Drosophila liquid facets

Suk Ho Eun 1, Kristi Lea 2, Erin Overstreet 3, Samuel Stevens 1, Ji-Hoon Lee 1 and Janice A Fischer 1*

1 University of Texas at Austin
2 Ambion, Inc
3 UCLA

* To whom correspondence should be addressed. E-mail: jaf{at}mail.utexas.edu.

Submitted on November 7, 2006
Revised on December 14, 2006
Accepted on 14 December 2006


Abstract

We have performed mutagenesis screens of the Drosophila X chromosome and the autosomes for dominant enhancers of the rough eye resulting from overexpression of liquid facets. The liquid facets gene encodes the homolog of vertebrate endocytic Epsin, an endocytic adapter protein. In Drosophila, Liquid facets is a core component of the Notch signaling pathway required in the signaling cells for ligand endocytosis and signaling. Why ligand internalization by the signaling cells is essential for signaling is a mystery. The requirement for Liquid facets is a hint at the answer, and the genes identified in this screen provide further clues. Mutant alleles of clathrin heavy chain, Rala, split ends, and auxilin were identified as enhancers. We describe the mutant alleles and mutant phenotypes of Rala and aux. We discuss the relevance of all of these genetic interactions to the function of Liquid facets in Notch signaling.

Key Words: Notch signaling, endocytosis, epsin, liquid facets, overexpression screen