Expression Of HSef In Various Human Tissues And Cell Lines

Fibroblast growth factor (FGF) signaling pathway plays an essential role in the embryo development, angiogenesis, wound recovery and tumorigenesis. Upon FGF binding, specific membrane receptors (FGFR) dimerize and autophosphorylate, then activate several downstream signaling pathways including Ras-MAPK. Activated FGFR phosphorylates Grb2, the activator of Ras. As a result, Ras was activated, which in turn tranduces the signal to Raf, MEK and ERK. At last activated ERK translocates into the nuclear and initiates gene transcription.Inappropriate activation of FGF signaling can cause development diseases and cancers, so its strength and duration must be accurately regulated. Sef (similar expression to fgf genes) is first identified as a feedback negative regulator of fibroblast growth factor (FGF) signaling in zebrafish, then in mouse and human. Overexpressed mSef inhibits FGF induced 3T3 cells proliferation and hSef inhibits FGF induced PC12 cells differentiation. However hSef's expression pattern in various tissues and cell lines is not reported.Here we report the expression and purification of GST-hSef fusion protein in E.coli, which was used for the preparation of polyclonal antibody from rabbit. hSef expressed in Cos-7 cells showed molecular weight of 80KD and 100KD respectively, slightly larger than that from in vitro translation result, which inferred the glycosylation at the potential N-linked glycosylation sites in the extracellular domain. Northern blot showed hSef mainly expressed in human kidney and testis tissues. Immunohistochemical analysis revealed high expression level of hSef in kidney, testis and the corresponding carcinoma tissues. RT-PCR analysis showed wide spread expression pattern in several cell lines.