Disease relevance of Cell Nucleolus

• The ultrastructural alterations of myocardial cell nucleoli may represent an important aspect of adriamycin toxicity [1].
• Human immunodeficiency virus type 1 encodes a positive trans-activator protein, Tat, which is located predominantly in the cell nucleolus [2].
• A 2'-O-methyltransferase that transfers the methyl group from S-adenosylmethionine to the 2'-hydroxyl group of ribose moieties of RNA has been purified from Ehrlich ascites tumor cell nucleoli [3].
• B23.1 purified from rat Novikoff hepatoma ascites cell nucleoli stimulated the activity of DNA polymerase alpha by as much as 3-to 4-fold in a dose-dependent manner, while it showed little effect on the activities of DNA polymerase beta, gamma, and primase [4].

High impact information on Cell Nucleolus

• U3, U8 and U13 comprise a new class of mammalian snRNPs localized in the cell nucleolus [5].
• The N-terminal 19 amino acids of rex-encoded protein (Rex) has been shown to be sufficient to direct hybrid proteins to the cell nucleolus [6].
• The posttranscriptional regulator (rex) of human T-cell leukemia virus type I is known to be located predominantly in the cell nucleolus and to induce the accumulation of gag and env viral mRNAs [6].
• Ultrastructural studies of the effects of adriamycin on liver and cardiac cell nucleoli of the rat showed that nucleolar segregation occurred within 1 hr after an i.v. injection of a 40-mg/kg dose [1].
• In the present study we examined the ultrastructural modifications as well as the precise distribution of DNA and RNA in RT4 cell nucleoli following a 3-h exposure to nontoxic or toxic doses of ametantrone (AMT), poly(adenylate-uridylate) (polyr(A-U), or an AMT/polyr(A-U) combination [7].

Biological context of Cell Nucleolus

• Rex is a phosphoprotein found predominantly in the cell nucleolus, whose function is thought to be regulated by its nucleolar localization and phosphorylation [8].

Anatomical context of Cell Nucleolus

• The polymorphic nucleoli of young tubule cells soon change to amphinucloeli and, while terminal nucleolar reorganization is delayed in cells of collecting tubules, in the nephrons nucleoli soon begin to undergo terminal reorganization becoming bipartite structures with separate plasmosomes and karyosomes [9].
• The agglomerates of extended nonnucleosomal DNA filaments were small and numerous in regenerating hepatocyte nucleoli, in which the RNP components had a nucleolonema-like distribution, whereas they were large and few in TG cell nucleoli, in which the RNP components showed a compact organization [10].

Associations of Cell Nucleolus with chemical compounds

• Immunoelectron microscope localization of bromodeoxyuridine incorporated into DNA of Ehrlich tumor cell nucleoli [11].
• But, unlike mammalian cell nucleoli, any fibrillar center has been observed in the Sf9 cell nucleolus, even after actinomycin D treatment [12].

Gene context of Cell Nucleolus

• In the present study, we analysed, on western blots, the AgNOR staining profiles obtained with protein extracts from Ehrlich tumor cell nucleoli isolated by a recent procedure that preserves the nucleolar ultrastructure [13].
• A chimeric Rex protein whose NOS region was substituted with the NOS of Rev was located predominantly in the cell nucleolus and functioned like the wild-type protein in the Rex assay system [14].
• The RNA distribution in Ehrlich tumour cell nucleoli has been investigated using RNase-gold method [15].
• In addition, for one-third of the 217 Arabidopsis nucleolar proteins, localization images are available from analysis of full-length cDNA-green fluorescent protein (GFP) fusions and the strength of signal in different parts of the cell-nucleolus, nucleolus-associated structures, nucleoplasm, nuclear bodies and extra-nuclear-is provided [16].

References