Related Experiment Video
Updated: Jul 6, 2026
07:35
Analysis of Spliceosomal snRNA Localization in Human Hela Cells Using Microinjection
Published on: August 6, 2019
Deciphering the assembly pathway of Sm-class U snRNPs
Nils Neuenkirchen1, Ashwin Chari, Utz Fischer
1Theodor-Boveri Institute at the Biocenter, Am Hubland, University of Wuerzburg, D-97074 Wuerzburg, Germany.
FEBS Letters
|March 20, 2008
Summary
The assembly of uridine-rich small nuclear ribonucleoproteins (U snRNPs) requires specific protein complexes. The survival motor neuron (SMN) and protein arginine methyltransferase 5 (PRMT5) complexes are crucial for U snRNP biogenesis.
Area of Science:
- Molecular Biology
- RNA Biology
- Cellular Processes
Background:
- The assembly of Sm-class uridine-rich small nuclear ribonucleoproteins (U snRNPs) is essential for pre-mRNA splicing.
- While U snRNP assembly is spontaneous in vitro, it requires numerous assisting factors in vivo.
- These factors are organized into two key interacting complexes: the survival motor neuron (SMN)-complex and the protein arginine methyltransferase 5 (PRMT5)-complex.
Purpose of the Study:
- To summarize recent advancements in understanding U snRNP assembly.
- To elucidate the roles of the SMN- and PRMT5-complexes in this process.
- To discuss the influence of these trans-acting factors on U snRNP biogenesis.
Main Methods:
- Review of recent scientific literature on U snRNP assembly.
- Analysis of the functional roles of SMN- and PRMT5-complexes.
- Discussion of the molecular mechanisms involved in U snRNP biogenesis.
Main Results:
- The PRMT5-complex initiates the assembly pathway by activating common U snRNP proteins.
- The SMN-complex facilitates the ordered and regulated incorporation of proteins and RNA.
- Both complexes are indispensable for the correct in vivo assembly of U snRNPs.
Conclusions:
- The SMN- and PRMT5-complexes play distinct yet cooperative roles in U snRNP assembly.
- Understanding these factors provides insights into the regulation of essential cellular machinery.
- Further research into these complexes can illuminate mechanisms of gene expression regulation.
Related Concept Videos
01:32RNA Splicing
Splicing is the process by which eukaryotic RNA is edited before its translation into protein. The RNA strand transcribed from eukaryotic DNA is called the primary transcript. The primary transcripts that become mRNAs are called precursor messenger RNAs (pre-mRNAs). Eukaryotic pre-mRNA contains alternating sequences of exons and introns. Exons are nucleotide sequences that code for proteins, whereas introns are the non-coding regions. In RNA splicing, introns are removed and exons are bonded...
01:32RNA Splicing
Splicing is the process by which eukaryotic RNA is edited before its translation into protein. The RNA strand transcribed from eukaryotic DNA is called the primary transcript. The primary transcripts that become mRNAs are called precursor messenger RNAs (pre-mRNAs). Eukaryotic pre-mRNA contains alternating sequences of exons and introns. Exons are nucleotide sequences that code for proteins, whereas introns are the non-coding regions. In RNA splicing, introns are removed and exons are bonded...
02:27Nonsense-mediated mRNA Decay
The Upf proteins that carry out nonsense-mediated decay (NMD) are found in all eukaryotic organisms, including humans. Each protein has an individual role, but they need to work in collaboration. Upf1 is an ATP-dependent RNA helicase that unwinds the RNA helix. Because Upf1 can unwind any RNA, Upf2 and Upf3 are required to help Upf1 discriminate between nonsense and normal mRNAs.
Usually, Upf3 binds to an Exon Junction Complex (EJC) at mRNA splice sites. If a ribosome fully translates the mRNA,...
Usually, Upf3 binds to an Exon Junction Complex (EJC) at mRNA splice sites. If a ribosome fully translates the mRNA,...
02:41Protein Complex Assembly
Proteins can form homomeric complexes with another unit of the same protein or heteromeric complexes with different types. Most protein complexes self-assemble spontaneously via ordered pathways, while some proteins need assembly factors that guide their proper assembly. Despite the crowded intracellular environment, proteins usually interact with their correct partners and form functional complexes.
Many viruses self-assemble into a fully functional unit using the infected host cell to...
Many viruses self-assemble into a fully functional unit using the infected host cell to...
02:53Ribosomal RNA Synthesis
Ribosome synthesis is a highly complex and coordinated process involving more than 200 assembly factors. The synthesis and processing of ribosomal components occurs not only in the nucleolus but also in the nucleoplasm and the cytoplasm of eukaryotic cells.
Ribosome biogenesis begins with the synthesis of 5S and 45S pre-rRNAs by distinct RNA polymerases. The primary transcripts are extensively processed and modified before they are bound and folded by ribosomal proteins and assembly factors,...
Ribosome biogenesis begins with the synthesis of 5S and 45S pre-rRNAs by distinct RNA polymerases. The primary transcripts are extensively processed and modified before they are bound and folded by ribosomal proteins and assembly factors,...
01:30Assembly of Signaling Complexes
Multiprotein signaling complexes are formed in a dynamic process involving protein-protein interactions at the cytoplasmic domain of transmembrane receptors or enzymatic and non-enzymatic proteins associated with the receptor. These complexes ensure the activation and propagation of intracellular signals that regulate cell functions.
Interaction domains in cell signaling
Interaction domains recognize exposed features of their binding partners containing post-translationally modified sequences,...
Interaction domains in cell signaling
Interaction domains recognize exposed features of their binding partners containing post-translationally modified sequences,...