Stat3 Is Present in the Developing and Adult Rat Cerebellum and Participates in the Formation of Transcription Complexes Binding DNA at the sis‐Inducible Element

Abstract

Stat3 is a member of a recently identified family of proteins named STATs for their ability to act as signal transducers and activators of transcription. Stimulation of epidermal growth factor or cytokine receptors can cause activation of Stat3 and transduction of specific responses to the nucleus. Here the presence of Stat3 has been examined in the rat cerebellum at different times during postnatal development and adulthood by means of immunohistochemistry and western blotting. In addition, DNA binding activity at the sis‐inducible element that is present in the promoter of the c‐fos gene has been studied by electrophoretic mobility shift assay. The results have shown that Stat3 p92 is abundant in the rat cerebellum. Stat3 was found in the external granule cell layer and also within the molecular layer from postnatal day (P) 0 to P7. From P15 to the adult, the internal granule cell layer and Purkinje cells were also stained for Stat3. Nuclear extracts were found to contain DNA binding activity to the sis‐inducible element during development and adulthood. Supershift assays demonstrated that Stat3 mediates the formation of one protein‐DNA complex. The present results suggest that Stat3 participates in intracellular signaling and is involved in maintaining basal c‐fos expression in the cerebellum of the developing and adult rat under physiological conditions.

Induction of gp130-related Cytokines and Activation of JAK2/STAT3 Pathway in Astrocytes Precedes Up-regulation of Glial Fibrillary Acidic Protein in the 1-Methyl-4-phenyl-1,2,3,6-tetrahydropyridine Model of Neurodegeneration

“…However, there is considerable variation in these reports with respect to the localization of activated STAT3. STAT3 phosphorylation has been reported to occur in neurons (46,48,49) and glial cells (11,14), and in some cases, specific insults cause the activation of STAT3 to occur in more than one cell type: neuron, astroglia, microglia, and/or endothelial cells (12)(13)(14). This makes it difficult to dissect the underlying signaling pathway leading to activation of STAT3 in vivo.…”

Phosphotyrosyl Peptides Block Stat3-mediated DNA Binding Activity, Gene Regulation, and Cell Transformation

“…To date, there are seven STAT family members identified in mammals, designated Stat1, Stat2, Stat3, Stat4, Stat5a, Stat5b, and Stat6. STATs have diverse normal biological functions, which include roles in cell differentiation, proliferation, development, apoptosis, and inflammation (7)(8)(9)(10)(11)(12)(13)(14)(15)(16)(17)(18). In addition to their roles in normal cellular processes, some STATs have been observed to participate in signaling events that lead to oncogenic transformation.…”

G-Quartet Oligonucleotides

“…STAT proteins, including Stat1, 2, 3, 4, 5a, 5b, and 6 link to a variety of cellular and biological processes including proliferation, differentiation, apoptosis, host defense, and transformation (2)(3)(4)(5)(6). STAT proteins are localized within the cytoplasm of resting cells and become activated by tyrosine phosphorylation at their COOH-terminal end (Y705) after recruitment to activated receptor complexes.…”