Cytoplasmic polyadenylation element cpe

Nucleotide sequence (often poly-U rich) that recruits the cytoplasmic polyadenylation element binding protein

(CPEB) to quiescent mRNA that has been stockpiled in the egg (and had the poly-A tail truncated). CPEB recruits a protein complex, called CPSF, which physically interacts with both CPEB and another sequence in the mRNA, to the 3' side of the CPE, called the nuclear polyadenylation hexanucleotide. This particular sequence (AAUAAA) is required for cytoplasmic polyadenylation. CPSF, once bound to the mRNA, recruits the enzyme poly A poly-merase to the mRNA.

cytoplasmic polyadenylation element binding factor CPEB A sequence-specific RNA-binding protein that controls polyadenylation-induced translation in germ cells and at postsynaptic sites of neurons. See cytoplasmic polyadenylation element and maskin.

cytoplasmic streaming Bulk flow of the cytoplasm of cells. Most conspicuous in large cells such as amoebae and the internodal cells of Chara, where the rate of movement may be as high as 100 |im/s. See cyclosis.

cytoplast Fragment of cell with nucleus removed (in kary-oplast); usually achieved by cytochalasin B treatment followed by mild centrifugation on a step gradient.

cytoproct Cell anus: region at posterior of a ciliate where exhausted food vacuoles are expelled.

cytorrhysis Process in which a plant cell wall collapses inward following water loss due to hyperosmotic stress. cf. plasmolysis.

cytosine Pyrimidine base found in DNA and RNA. Pairs with guanine. Glycosylated base is cytidine.

cytosine arabinoside Cytarabine Cytotoxic drug used in oncology (particularly AML) and against viral infections. Blocks DNA synthesis.

cytoskeleton General term for the internal components of animal cells which give them structural strength and motility: plant cells and bacteria use an extracellular cell wall instead. The major components of cytoskeleton are the microfilaments (of actin), microtubules (of tubulin) and intermediate filament systems in cells.

cytosol That part of the cytoplasm that remains when organelles and internal membrane systems are removed.

cytosome 1. The body of a cell apart from its nucleus. 2. A multilamellar body found in cells of the lung.

cytostome A specialized region of various protozoans in which phagocytosis is likely to occur. Often there is a clear concentration of microtubules or/and microfilaments in the region of the cytostome. In ciliates there may be a specialized arrangement of cilia around the cytostome.

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