The FRK/RAK-SHB signaling cascade: a versatile signal-transduction pathway that regulates cell survival, differentiation and profileration
2003 (English)In: Current molecular medicine, ISSN 1566-5240, Vol. 3, no 4, 313-324 p.Article in journal (Refereed) Published
Recent experiments have unravelled novel signal transduction pathways that involve the SRC homology 2 (SH2) domain adapter protein SHB. SHB is ubiquitously expressed and contains proline rich motifs, a phosphotyrosine binding (PTB) domain, tyrosine phosphorylation sites and an SH2 domain and serves a role in generating signaling complexes in response to tyrosine kinase activation. SHB mediates certain responses in platelet-derived growth factor (PDGF) receptor-, fibroblast growth factor (FGF) receptor-, neural growth factor (NGF) receptor TRKA-, T cell receptor-, interleukin-2 (IL-2) receptor- and focal adhesion kinase- (FAK) signaling. Upstream of SHB in some cells lies the SRC-like FYN-Related Kinase FRK / RAK (also named BSK / IYK or GTK). FRK / RAK and SHB exert similar effects when overexpressed in rat phaeochromocytoma (PC12) and β-cells, where they both induce PC12 cell differentiation and β-cell proliferation. Furthermore, β-cell apoptosis is augmented by these proteins under conditions that cause β-cell degeneration. The FRK / RAK-SHB responses involve FAK and insulin receptor substrates (IRS) -1 and -2.
Besides regulating apoptosis, proliferation and differentiation, SHB is also a component of the T cell receptor (TCR) signaling response. In Jurkat T cells, SHB links several signaling components with the TCR and is thus required for IL-2 production. In endothelial cells, SHB both promotes apoptosis under conditions that are anti-angiogenic, but is also required for proper mitogenicity, spreading and tubular morphogenesis. In embryonic stem cells, dominant-negative SHB (R522K) prevents early cavitation of embryoid bodies and reduces differentiation to cells expressing albumin, amylase, insulin and glucagon, suggesting a role of SHB in development.
In summary, SHB is a versatile signal transduction molecule that produces diverse biological responses in different cell types under various conditions. SHB operates downstream of GTK in cells that express this kinase.
Place, publisher, year, edition, pages
Bentham , 2003. Vol. 3, no 4, 313-324 p.
signal-transduction pathway, proliferation, src homology 2, sh2 domain adapter protein
Cell and Molecular Biology
IdentifiersURN: urn:nbn:se:uu:diva-65508PubMedID: 12776987OAI: oai:DiVA.org:uu-65508DiVA: diva2:93419