RGD Reference Report - S100B Protein Regulates Astrocyte Shape and Migration via Interaction with Src Kinase: IMPLICATIONS FOR ASTROCYTE DEVELOPMENT, ACTIVATION, AND TUMOR GROWTH. - Rat Genome Database

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S100B Protein Regulates Astrocyte Shape and Migration via Interaction with Src Kinase: IMPLICATIONS FOR ASTROCYTE DEVELOPMENT, ACTIVATION, AND TUMOR GROWTH.

Authors: Brozzi, F  Arcuri, C  Giambanco, I  Donato, R 
Citation: Brozzi F, etal., J Biol Chem. 2009 Mar 27;284(13):8797-811. Epub 2009 Jan 15.
RGD ID: 5508832
Pubmed: (View Article at PubMed) PMID:19147496
DOI: Full-text: DOI:10.1074/jbc.M805897200

S100B is a Ca(2+)-binding protein of the EF-hand type that is abundantly expressed in astrocytes and has been implicated in the regulation of several intracellular activities, including proliferation and differentiation. We show here that reducing S100B levels in the astrocytoma cell line GL15 and the Muller cell line MIO-M1 by small interference RNA technique results in a rapid disassembly of stress fibers, collapse of F-actin onto the plasma membrane and reduced migration, and acquisition of a stellate shape. Also, S100B-silenced GL15 and MIO-M1 Muller cells show a higher abundance of glial fibrillary acidic protein filaments, which mark differentiated astrocytes, compared with control cells. These effects are dependent on reduced activation of the phosphatidylinositol 3-kinase (PI3K) downstream effectors, Akt and RhoA, and consequently elevated activity of GSK3beta and Rac1 and decreased activity of the RhoA-associated kinase. Also, rat primary astrocytes transiently down-regulate S100B expression when exposed to the differentiating agent dibutyryl cyclic AMP and re-express S100B at later stages of dibutyryl cyclic AMP-induced differentiation. Moreover, reducing S100B levels results in a remarkably slow resumption of S100B expression, suggesting the S100B might regulate its own expression. Finally, we show that S100B interacts with Src kinase, thereby stimulating the PI3K/Akt and PI3K/RhoA pathways. These results suggest that S100B might contribute to reduce the differentiation potential of cells of the astrocytic lineage and participate in the astrocyte activation process in the case of brain insult and in invasive properties of glioma cells.



Disease Annotations    
brain edema  (IEP,ISO)
Hematoma  (IEP,ISO)

Gene Ontology Annotations    

Biological Process

Objects Annotated

Genes (Rattus norvegicus)
S100b  (S100 calcium binding protein B)

Genes (Mus musculus)
S100b  (S100 protein, beta polypeptide, neural)

Genes (Homo sapiens)
S100B  (S100 calcium binding protein B)


Additional Information