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Snurposome
A snurposome is a granular structure in the nuclei of amphibian oocytes. Snurposomes contain snRNP snRNPs (pronounced "snurps"), or small nuclear ribonucleoproteins, are RNA-protein complexes that combine with unmodified pre-mRNA and various other proteins to form a spliceosome, a large RNA-protein molecular complex upon which splicing of pre- ...s and are divided into the subtypes A, B, and C. A B snurposome is composed of thousands of particles which have diameters between 20 and 30 nanometers. B snurposomes may be forms of splicing speckles. References * * Nuclear substructures {{cell-biology-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Splicing Speckles
The cell nucleus (pl. nuclei; from Latin or , meaning ''kernel'' or ''seed'') is a membrane-bound organelle found in eukaryotic cells. Eukaryotic cells usually have a single nucleus, but a few cell types, such as mammalian red blood cells, have no nuclei, and a few others including osteoclasts have many. The main structures making up the nucleus are the nuclear envelope, a double membrane that encloses the entire organelle and isolates its contents from the cellular cytoplasm; and the nuclear matrix, a network within the nucleus that adds mechanical support. The cell nucleus contains nearly all of the cell's genome. Nuclear DNA is often organized into multiple chromosomes – long stands of DNA dotted with various proteins, such as histones, that protect and organize the DNA. The genes within these chromosomes are structured in such a way to promote cell function. The nucleus maintains the integrity of genes and controls the activities of the cell by regulating gene express ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
SnRNP
snRNPs (pronounced "snurps"), or small nuclear ribonucleoproteins, are RNA-protein complexes that combine with unmodified pre-mRNA and various other proteins to form a spliceosome, a large RNA-protein molecular complex upon which splicing of pre-mRNA occurs. The action of snRNPs is essential to the removal of introns from pre-mRNA, a critical aspect of post-transcriptional modification of RNA, occurring only in the nucleus of eukaryotic cells. Additionally, '' U7 snRNP'' is not involved in splicing at all, as U7 snRNP is responsible for processing the 3′ stem-loop of histone pre-mRNA. The two essential components of snRNPs are protein molecules and RNA. The RNA found within each snRNP particle is known as ''small nuclear RNA'', or snRNA, and is usually about 150 nucleotides in length. The snRNA component of the snRNP gives specificity to individual introns by " recognizing" the sequences of critical splicing signals at the 5' and 3' ends and branch site of introns. The snRN ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
