Fig. 4

GroPIns4P favours the association between Shp1 and Src. a, c, e Interaction between Src and Shp1 wild type (a, Shp WT), Shp1-C455S (c, Shp1-C455S) or Shp1-S118A/R138E/S140A mutant (e, Shp1-S118A/R138E/S140A) was examined by immunoprecipitation (IP) with an anti-Shp1 antibody in serum-starved NIH3T3 cells over-expressing Shp1 WT, Shp1-C455S or Shp1-S118A/R138E/S140A mutant untreated (−) or treated (+) with 50 μM GroPIns4P for 5 min (as indicated). The expression levels of Shp1 WT, Shp1-C455S, Shp1-S118A/R138E/S140A and Src, examined in total lysates (input) indicate comparable amounts of proteins. Molecular weight standards (kDa) are indicated on the right of each panel. b, d, f Quantification of co-immunoprecipitated Src with Shp1 WT (b), Shp1-C455S (d) or Shp1-S118A/R138E/S140A mutant (f) using ImageJ analysis software. Data (GroPIns4P) are expressed as percentages of untreated sample (untreated) and as the means (±SD) of at least three independent experiments (Shp1 WT n = 4; Shp1-C455S n = 4; Shp1-S118A/R138E/S140A n = 3). *P < 0.05 (Student’s t-test)