Nef stimulates proliferation of glomerular podocytes through activation of Src-dependent Stat3 and MAPK1,2 pathways
J. Clin. Invest. John Cijiang He, et al. 114:643 doi:10.1172/JCI21004 [Go to this article.]

Figure 1
Nef activates the Src-Stat3 pathway. Podocytes were infected with nef-containing vector (Nef) or control vectors (V) as described, and differentiation was induced at 37°C on collagen I for 10 days. (A) Src kinase activity was determined by an in vitro phosphorylation assay as described in Methods. Densitometric data: Src activity/Src protein ratio: V = 0.15 ± 0.02, Nef = 0.45 ± 0.05, P < 0.05, n = 3. (B) Both phosphorylated and total Src and Stat3 were detected by Western blot as described in Methods. Densitometric data: phospho-Src/total Src ratio: V = 0.13 ± 0.02, Nef = 0.40 ± 0.04, V + PP2 = 0.14 ± 0.05, Nef + PP2 = 0.22 ± 0.07, P < 0.05 when Nef is compared with Nef + PP2, n = 4; phospho-Stat3/total Stat3 ratio: V = 0.24 ± 0.05, Nef = 0.65 ± 0.07, V + PP2 = 0.14 ± 0.06, Nef + PP2 = 0.18 ± 0.07, P < 0.01 when Nef is compared with V or with Nef + PP2, n = 4. (C) Phosphorylation of Hck and Fyn was also detected using the same method as that described for Src. Densitometric data: phospho-Hck/total Hck ratio: V = 0.93 ± 0.25, Nef = 0.98 ± 0.32; phospho-Fyn/total Fyn ratio: V = 0.94 ± 0.30, Nef = 1.05 ± 0.35; P = NS, n = 3.