Nucleophosmin/B23 (NPM/B23), a nucleolar protein, was rapidly up-regulated after UV irradiation (at 254 nm; 30 J/m(2)) in NIH 3T3 cells and HeLa/S3 cells. Levels of NPM/B23 mRNA peaked 45-60 min after UV treatment and returned to baseline by 12 h. Transcription inhibitor actinomycin D (5 microg/ml) prevented the UV-induced increase of NPM/B23 mRNA, suggesting that UV induction of NPM/B23 was me...

Nucleophosmin (NPM/B23) is a key regulator in the regulation of a number of processes including centrosome duplication, maintenance of genomic integrity, and ribosome biogenesis. While the mechanisms underlying NPM function are largely uncharacterized, NPM loss results in severe dysregulation of developmental and growth-related events. We show that NPM utilizes a conserved CRM1-dependent nuclea...

Anaplastic large cell lymphomas (ALCL) are characterized by the expression of a chimeric protein, NPM-ALK, which originates from fusion of the nucleophosmin (NPM) and the membrane receptor anaplastic lymphoma kinase (ALK) genes. The NPM-ALK kinase, on dimerization, shows phosphotransferase activity and, through its interaction with various ALK-adapter proteins, induces cell transformation and i...

BACKGROUND Inhalation of airborne particulate matter (PM) derived from urban traffic is associated with pathology in the arteries, heart, and lung; effects on brain are also indicated but are less documented. OBJECTIVE We evaluated rodent brain responses to urban nanoscale (< 200 nm) PM (nPM). METHODS Ambient nPM collected near an urban freeway was transferred to aqueous suspension and reae...

More than half of anaplastic large-cell lymphomas (ALCLs) have a chromosomal translocation t(2;5) that leads to the expression of a hybrid protein composed of the nucleolar phosphoprotein nucleophosmin (NPM) and the anaplastic lymphoma kinase (ALK) that exhibits an unregulated tyrosine kinase activity. We have previously identified PLC-gamma as a crucial downstream signaling molecule of NPM-ALK...

The Arf tumor suppressor inhibits cell cycle progression through both p53-dependent and p53-independent mechanisms, including interference with rRNA processing. Using tandem-affinity-tagged p19(Arf), we purified Arf-associated proteins from mouse NIH 3T3 fibroblasts undergoing cell cycle arrest. Tagged p19(Arf) associated with nucleolar and ribosomal proteins, including nucleophosmin/B23 (NPM),...

Nucleophosmin (NPM) is an important nucleolar phosphoprotein with pleiotropic functions in various cellular processes. In this study, we have further examined the largely uncharacterized role of NPM in transcriptional regulation by uncovering novel NPM-binding transcriptional factors. Among potential interactors, we found that activating protein transcription factor 2 (AP2)alpha forms a complex...

Anaplastic large-cell lymphoma (ALCL) is frequently associated with the 2;5 translocation and expresses the NPM-ALK fusion protein, which possesses a constitutive tyrosine kinase activity. We analyzed SHP1 tyrosine phosphatase expression and activity in 3 ALK-positive ALCL cell lines (Karpas 299, Cost, and SU-DHL1) and in lymph node biopsies (n = 40). We found an inverse correlation between the...