The nucleolus is a plurifunctional organelle with dynamic protein exchange involved in diverse aspects of cell biology. Additionally, the nucleolus has been shown to have a role in the replication of numerous viruses, which includes HIV-1. Several groups have reported HIV-1 vRNA localization within the nucleolus. Moreover, it has been demonstrated the HIV-1 Rev protein localizes to the nucleolu...

I n eukaryotic cells containing tandem repeated ribosomal RNA genes, there appears a specialized region of chromatin, carrying out gene transcription, rRNA processing, and nascent ribosomal subunit assembly—the nucleolus. One of the first intracellular structures to be described (Montgomery, 1898; Franke, 1988), the nucleolus was established in the 1960s as the center of ribosome synthesis (Sch...

Immortal DNA arpowicz et al. (page 721) report evidence for asymmetric segregation of the oldest DNA during neural stem cell proliferation. According to the immortal strand hypothesis, which was first proposed in the mid-1970s, stem cells actively retain the oldest DNA during asymmetric cell divisions. That DNA should, statistically speaking, contain fewer replication-induced errors than DNA re...

Interphase, preprophase, and prophase nuclei of meristematic cells of Allium cepa, Vicia faba, and Raphanus sativus are characterized by the presence of spherical bodies approximately 1 micro in diameter. These structures are Feulgen-negative but stain metachromatically with azure B, as the nucleolus, following fixation with glutaraldehyde. At the ultrastructural level, they consist predominant...

The classical view of the nucleolus as solely committed to ribosome biosynthesis has been modified by recent studies pointing to additional roles for this nuclear domain. These newly recognized features include the nucleolar presence of several nonribosomal RNAs transcribed by RNA polymerase III, as well as nucleolar roles in gene silencing, cell cycle progression, and cellular senescence. The ...

In Trypanosoma brucei, transcription by RNA polymerase II and 5' capping of messenger RNA are uncoupled: a capped spliced leader is trans spliced to every RNA. This decoupling makes it possible to have protein-coding gene transcription driven by RNA polymerase I. Indeed, indirect evidence suggests that the genes for the major surface glycoproteins, variant surface glycoproteins (VSGs) in bloods...

Chinese hamster cell strains in the early passages in culture display wide variation in number of nucleolus-like bodies per cell, though such strains are characteristically euploid. A variety of criteria indicate that the nucleolus-like bodies are true nucleoli. Their Azure B- and fast green-staining properties indicate the presence of RNA and protein; they have typical nucleolar fine structure...

The nucleolus is a prominent nuclear structure that is the site of ribosomal RNA (rRNA) transcription, and hence ribosome biogenesis. Cellular demand for ribosomes, and hence rRNA, is tightly linked to cell growth and the rRNA makes up the majority of all the RNA within a cell. To fulfill the cellular demand for rRNA, the ribosomal RNA (rDNA) genes are amplified to high copy number and transcri...

Weighted voting games (WVG) are coalitional games in which an agent’s contribution to a coalition is given by his weight, and a coalition wins if its total weight meets or exceeds a given quota. These games model decision-making in political bodies as well as collaboration and surplus division in multiagent domains. The computational complexity of various solution concepts for weighted voting g...

Polyphosphoinositides (PPIns) are present in the nucleus where they participate in crucial nuclear processes, such as chromatin remodelling, transcription and mRNA processing. In a previous interactomics study, aimed to gain further insight into nuclear PPIns functions, we identified ErbB3 binding protein 1 (EBP1) as a potential nuclear PPIn-binding protein in a lipid pull-down screen. EBP1 is ...