What are u snRNPs?

What are u snRNPs?

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.

What do snRNAs do?

Small nuclear RNA (snRNA) is a class of small RNA molecules that are found within the splicing speckles and Cajal bodies of the cell nucleus in eukaryotic cells. Their primary function is in the processing of pre-messenger RNA (hnRNA) in the nucleus.

What is the difference between snRNA and snRNP?

The term “snRNA” stands for small nuclear RNAs. snRNAs combined with proteins make up snRNPs , which are small nuclear RNA molecules and proteins. A snRNP requires both the RNA and protein components to splice out introns. It is the RNA component that has the enzymatic activity and makes the endonuclease cuts.

Who was the first person to discover the snRNP?

SnRNPs were discovered by Michael R. Lerner and Joan A. Steitz. Thomas R. Cech and Sidney Altman also played a role in the discovery, winning the Nobel Prize for Chemistry in 1989 for their independent discoveries that RNA can act as a catalyst in cell development.

What are the antigenic sites of RNP and SM?

It has been shown that RNP and Sm are distinct antigenic sites on the same nuclear molecular matrix consisting of RNA and eight polypeptides, including 70 kD, A (33 kD), C (22 kD) and the Sm peptides B (26 kD), B’ (27 kD), D (13 kD), E/F (11 kD doublet), and G (9 kD).

Where does the biogenesis of the snRNP take place?

This consists of additional proteins and other modifications specific to the particular snRNP (U1, U2, U4, U5). The biogenesis of the U6 snRNP occurs in the nucleus, although large amounts of free U6 are found in the cytoplasm. The LSm ring may assemble first, and then associate with the U6 snRNA .

Is the snRNP a long-lived organism or is it degraded?

The snRNPs are very long-lived, but are assumed to be eventually disassembled and degraded. Little is known about the degradation process.