title: Sprouty is a cytoplasmic target of adenoviral E1A oncoproteins to regulate the receptor tyrosine kinase signalling pathway.
abstract: BACKGROUND
  Oncoproteins encoded by the early region of adenoviruses have been shown to be powerful tools to study gene regulatory mechanisms, which affect major cellular events such as proliferation, differentiation, apoptosis and oncogenic transformation. They are possesing a key role to favor viral replication via their interaction with multiple cellular proteins. In a yeast two-hybrid screen we have identified Sprouty1 (Spry1) as a target of adenoviral E1A Oncoproteins. Spry proteins are central and complex regulators of the receptor tyrosine kinase (RTK) signalling pathway. The deregulation of Spry family members is often associated with alterations of the RTK signalling and its downstream effectors, leading to the ERK pathway.
  
  
  RESULTS
  Here, we confirm our yeast two-hybrid data, showing the interaction between Spry1 and E1A in GST pull-down and immunoprecipitation assays. We also demonstrated the interaction of E1A with two further Spry isoforms. Using deletion mutants we identified the N-terminus and the CR conserved region (CR) 3 of E1A- and the C-terminal half of Spry1, which contains the highly conserved Spry domain, as the essential sites for direct interaction between Spry and E1A. Immunofluorescent microscopy data revealed a co-localization of E1A(13S) with Spry1 in the cytoplasm. SRE and TRE reporter assays demonstrated that co-expression of Spry1 with E1A(13S) abolishes the inhibitory function of Spry1 in RTK signalling, which is consequently accompanied with a decrease of E1A13S-induced gene expression.
  
  
  CONCLUSIONS
  These results establish Spry1 as a cytoplasmic localized cellular target for E1A oncoproteins to regulate the RTK signalling pathway, and consequently cellular events downstream of RTK that are essential for viral replication and transformation.
authors.affiliation: Laboratory of Signal Transduction, National Institute of Environmental Health Sciences, Research Triangle Park, PO Box 12233, Durham, NC 27709, USA. zarembaa@niehs.nih.gov
authors.forename: Angelika
authors.initials: A
authors.lastname: Zaremba
authors.forename: Ursula
authors.initials: U
authors.lastname: Schmuecker
authors.forename: Helmut
authors.initials: H
authors.lastname: Esche
mesh_terms: D048868:Adaptor Proteins, Signal Transducing; D000256:Adenoviridae / Q000472:pathogenicity*; D017500:Adenovirus E1A Proteins / Q000378:metabolism*; D000818:Animals; D002460:Cell Line; D003593:Cytoplasm / Q000737:chemistry; D008565:Membrane Proteins / Q000378:metabolism*; D051379:Mice; D008856:Microscopy, Fluorescence; D010750:Phosphoproteins / Q000378:metabolism*; D025941:Protein Interaction Mapping; D011505:Protein-Tyrosine Kinases / Q000378:metabolism*; D017384:Sequence Deletion; D015398:Signal Transduction; D020798:Two-Hybrid System Techniques
chemical_list: D048868:Adaptor Proteins, Signal Transducing; D017500:Adenovirus E1A Proteins; D008565:Membrane Proteins; D010750:Phosphoproteins; C486055:SPRY1 protein, human; C425468:Spry1 protein, mouse; D011505:Protein-Tyrosine Kinases