title: Mtl interacts with members of Egfr signaling and cell adhesion genes in the Drosophila eye.
abstract: Mtl is a member of the Rho family of small GTPases in Drosophila. It was shown that Mtl is involved in planar cell polarity (PCP) establishment, together with other members of the same family like Cdc42, Rac1, Rac2 and RhoA. However, while Rac1, Rac2 and RhoA function downstream of Dsh in Fz/PCP signaling and upstream of a JNK cassette, Mtl and Cdc42 do not. To determine the functional context of Mtl during PCP establishment in the Drosophila eye, we performed a loss-of-function screen to search for dominant modifiers of a sev>Mtl rough eye phenotype. In addition, genetic interaction assays with candidate genes were also carried out. Our results show that Mtl interacts genetically with members and effectors of Egfr signaling, with components and/or regulators of other signal transduction pathways, and with genes involved in cell adhesion and cytoskeleton organization. One of these genes is hibris (hbs), which encodes a member of the immunoglobulin superfamily in Drosophila. Phenotypic analyses and genetic interaction assays suggest that it may have a role during PCP establishment, interacting with both Egfr and Fz/PCP signaling during this process. Taken together, our results indicate that Mtl is functionally related to the Egfr pathway regulating ommatidial rotation during PCP establishment in the eye, being a positive regulator of this pathway. Since Egfr signaling is linked to cytoskeletal and cell junctional elements, it is likely that Mtl may be regulating cytoskeleton dynamics and thus cell adhesion during ommatidial rotation in the context of that pathway.
authors: Department of Genetics, Facultad CC Biológicas, Universidad de Valencia, Burjasot, Valencia, Spain.
authors: Verónica
authors: V
authors: Muñoz-Soriano
authors: Yaiza
authors: Y
authors: Belacortu
authors: Fabrice C
authors: FC
authors: Durupt
authors: Silvia
authors: S
authors: Muñoz-Descalzo
authors: Nuria
authors: N
authors: Paricio
mesh_terms: D000818:Animals; D002448:Cell Adhesion / Q000235:genetics*; D016764:Cell Polarity / Q000235:genetics; D054910:Compound Eye, Arthropod / Q000166:cytology / Q000378:metabolism / Q000648:ultrastructure; D004330:Drosophila / Q000166:cytology / Q000235:genetics / Q000378:metabolism*; D029721:Drosophila Proteins / Q000235:genetics / Q000378:metabolism*; D066246:ErbB Receptors / Q000235:genetics / Q000378:metabolism*; D010641:Phenotype; D018010:Receptors, Invertebrate Peptide / Q000235:genetics / Q000378:metabolism*; D015398:Signal Transduction; D020741:rho GTP-Binding Proteins / Q000235:genetics / Q000378:metabolism*
chemical_list: D029721:Drosophila Proteins; D018010:Receptors, Invertebrate Peptide; C066532:Egfr protein, Drosophila; D066246:ErbB Receptors; C560746:Mtl protein, Drosophila; D020741:rho GTP-Binding Proteins