Human 14-3-3 gamma protein results in abnormal cell proliferation in the developing eye of Drosophila melanogaster

Sophia W Hong¹ , Wenqing Qi² , Marc Brabant³ , Giovanni Bosco⁴ and Jesse D Martinez¹

¹Department of Cell Biology and Anatomy, Arizona Cancer Center, University of Arizona, Tucson, Arizona 85724, USA

²Department of Medicine, Arizona Cancer Center, University of Arizona, Tucson, Arizona 85724, USA

³Cancer Center Division, Arizona Cancer Center, University of Arizona, Tucson, Arizona 85724, USA

⁴Department of Molecular and Cellular Biology, University of Arizona, Tucson, Arizona 85721, USA

author email corresponding author email

Cell Division 2008, 3:2doi:10.1186/1747-1028-3-2


Published:	14 January 2008

Abstract

Background

14-3-3 proteins are a family of adaptor proteins that participate in a wide variety of cellular processes. Recent evidence indicates that the expression levels of these proteins are elevated in some human tumors providing circumstantial evidence for their involvement in human cancers. However, the mechanism through which these proteins act in tumorigenesis is uncertain.

Results

To determine whether elevated levels of 14-3-3 proteins may perturb cell growth we overexpressed human 14-3-3 gamma (h14-3-3 gamma) in Drosophila larvae using the heat shock promoter or the GMR-Gal4 driver and then examined the effect that this had on cell proliferation in the eye imaginal discs of third instar larvae. We found that induction of h14-3-3 gamma resulted in the abnormal appearance of replicating cells in the differentiating proneural photoreceptor cells of eye imaginal discs where h14-3-3 gamma was driven by the heat shock promoter. Similarly, we found that driving h14-3-3 gamma expression specifically in developing eye discs with the GMR-Gal4 driver resulted in increased numbers of replicative cells following the morphogenetic furrow. Interestingly, we found that the effects of overexpressing h1433 gamma on eye development were increased in a genetic background where String (cdc25) function was compromised.

Conclusion

Taken together our results indicate that h14-3-3 gamma can promote abnormal cell proliferation and may act through Cdc25. This has important implications for 14-3-3 gamma as an oncogene as it suggests that elevated levels of 14-3-3 may confer a growth advantage to cells that overexpress it.