N. A. Thompson

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The homeodomain protein PDX-1, referred as IPF-1/STF-1/IDX-1, is a transcriptional factor that plays a critical role in the control of several genes expressed in the pancreatic islet. PDX-1 gene expression has been previously shown to be reduced in cultured beta-cell lines chronically exposed to high glucose concentrations. As the glucose transporter type 2(More)
Macrophage migration inhibitory factor (MIF), originally identified as a cytokine secreted by T lymphocytes, was found recently to be both a pituitary hormone and a mediator released by immune cells in response to glucocorticoid stimulation. We report here that the insulin-secreting beta cell of the islets of Langerhans expresses MIF and that its production(More)
Transferrin receptor (TfR) mRNA expression is tightly linked to intracellular iron levels. Upon iron deprivation, the iron regulatory protein (IRP) stabilizes TfR mRNA by binding to stem-loop structures in its 3'-untranslated region, whereas increased iron levels result in inactivation of the mRNA-binding protein and rapid degradation of TfR mRNA. Although(More)
Neuropeptide-Y (NPY) is a 36-amino acid peptide known to inhibit glucose-stimulated insulin secretion in various animal models in vitro and in vivo. NPY is thought to be one of the mediators of sympathetic action in the pancreas through nerve endings surrounding the islets, and it has recently been shown to be synthesized within the islets of Langerhans. To(More)
The murine histocompatibility class I genes, H-2 Kb and Kk, display considerable homology at their 3' ends. In fact, from exon 5 to the termination codon, only two nucleotides differ between the two genes, one at the 5' end and the other at the 3' end of intron 7. Despite this similarity, the gene products have distinctly different mol. wts as determined by(More)
Macrophage migration-inhibitory factor (MIF) has recently been identified as a pituitary hormone that functions as a counterregulatory modulator of glucocorticoid action within the immune system. In the anterior pituitary gland, MIF is expressed in TSH- and ACTH-producing cells, and its secretion is induced by CRF. To investigate MIF function and regulation(More)
In pancreatic beta-cells, the high Km glucose transporter GLUT2 catalyzes the first step in glucose-induced insulin secretion by glucose uptake. Expression of the transporter has been reported to be modulated by glucose either at the protein or mRNA levels. In this study we used the differentiated insulinoma cell line INS-1 which expresses high levels of(More)
A defect in glucose sensing of the pancreatic beta-cells has been observed in several animal models of type II diabetes and has been correlated with a reduced gene expression of the glucose transporter type 2 (Glut2). In a transgenic mouse model, expression of Glut2 antisense RNA in pancreatic beta-cells has recently been shown to be associated with an(More)
Islet-brain1/JNK-interacting protein-1 (IB1/JIP-1) is a scaffold protein that organizes the JNK, MKK7, and MLK1 to allow signaling specificity. Targeted disruption of the gene MAPK8IP1 encoding IB1/JIP-1 in mice led to embryonic death prior to blastocyst implantation. In culture, no IB1/JIP-1(-/-) embryos were identified indicating that accelerated cell(More)
We describe a simple method for the affinity purification of specific RNA-binding proteins. DNA sequences corresponding to the protein-binding site of the RNA are subcloned into an in vitro transcription vector between the T7 viral promoter and a poly(A) track. A polyadenylated RNA transcript is bound to poly(U)-Sepharose and subsequently incubated with a(More)