Related Experiment Video

Updated: Sep 6, 2026

Determining Genetic Expression Profiles in C. elegans Using Microarray and Real-time PCR
10:27

Determining Genetic Expression Profiles in C. elegans Using Microarray and Real-time PCR

Published on: July 30, 2011

SMG-5, required for C.elegans nonsense-mediated mRNA decay, associates with SMG-2 and protein phosphatase 2A

Kirk R Anders1, Andrew Grimson, Philip Anderson

  • 1Department of Genetics, University of Wisconsin-Madison, Madison, WI 53706, USA.

The EMBO Journal
|January 30, 2003
PubMed

Insights

Nonsense-mediated mRNA decay (NMD) degrades faulty mRNAs. The SMG-5 protein interacts with protein phosphatase 2A (PP2A) to dephosphorylate SMG-2, a key step in this essential eukaryotic process.

Area of Science:

  • Molecular Biology
  • Genetics
  • Cell Biology

Background:

  • Nonsense-mediated mRNA decay (NMD) is a crucial surveillance pathway in eukaryotes.
  • NMD selectively degrades messenger RNAs (mRNAs) containing premature stop codons.
  • The smg-5 gene encodes a protein vital for NMD in Caenorhabditis elegans.

Purpose of the Study:

  • To elucidate the molecular function of SMG-5 in NMD.
  • To identify protein interactions involving SMG-5.
  • To understand the mechanism of SMG-2 dephosphorylation in NMD.

Main Methods:

  • Immunoprecipitation assays to detect protein-protein interactions.
  • Yeast two-hybrid assays for identifying interacting partners.
  • Analysis of protein phosphorylation and dephosphorylation in NMD.

Main Results:

  • SMG-5 interacts with SMG-7, SMG-2, PR65 (PP2A structural subunit), and PP2A(C) (PP2A catalytic subunit).
  • SMG-5 and SMG-7 are essential for SMG-2 dephosphorylation.
  • Results suggest PP2A acts as the SMG-2 phosphatase, with SMG-5 directing PP2A to SMG-2.

Conclusions:

  • SMG-5 plays a critical role in NMD by facilitating the dephosphorylation of SMG-2 via PP2A.
  • The interaction between SMG-5 and PP2A is key to targeting the SMG-2 substrate.
  • Understanding these phosphorylation cycles provides insight into NMD regulation.

More Related Videos

Detecting Protein Subcellular Localization by Green Fluorescence Protein Tagging and 4',6-Diamidino-2-phenylindole Staining in Caenorhabditis elegans09:36

Detecting Protein Subcellular Localization by Green Fluorescence Protein Tagging and 4',6-Diamidino-2-phenylindole Staining in Caenorhabditis elegans

Published on: July 30, 2018

CRISPR/Cas9 Editing of the C. elegans rbm-3.2 Gene using the dpy-10 Co-CRISPR Screening Marker and Assembled Ribonucleoprotein Complexes.07:46

CRISPR/Cas9 Editing of the C. elegans rbm-3.2 Gene using the dpy-10 Co-CRISPR Screening Marker and Assembled Ribonucleoprotein Complexes.

Published on: December 11, 2020

Related Concept Videos

Nuclear Export of mRNA02:31

Nuclear Export of mRNA

Before mRNAs are exported to the cytoplasm, it is crucial to check each mRNA for structural and functional integrity. Eukaryotic cells use several different mechanisms, collectively known as mRNA surveillance, to look for irregularities in mRNAs. Irregular or aberrant mRNA are rapidly degraded by various enzymes. If a defective mRNA escapes the surveillance, it would be translated into a protein which would either be non-functional or not function properly. One of the primary irregularities in...
Nonsense-mediated mRNA Decay02:27

Nonsense-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,...
Regulation of Expression Occurs at Multiple Steps02:24

Regulation of Expression Occurs at Multiple Steps

Gene expression can be regulated at almost every step from gene to protein. Transcription is the step that is most commonly regulated. This involves the binding of proteins to short regulatory sequences on the DNA. This association can either promote or inhibit the transcription of a gene associated with the respective sequence.
Transcription results in the generation of precursor (pre-mRNA) that consists of both exons and introns, which needs further processing before being translated to a...
mRNA Stability and Gene Expression02:51

mRNA Stability and Gene Expression

The structure and stability of mRNA molecules regulates gene expression, as mRNAs are a key step in the pathway from gene to protein. In eukaryotes, the half-life of mRNA varies from a few minutes up to several days. mRNA stability is essential in growth and development. The absence of the proteins regulating its stability, such as tristetraprolin in mice, can cause systemic issues, including bone marrow overgrowth, inflammation, and autoimmunity.
Cis-acting Elements involved in mRNA stability
Regulation of Nuclear Protein Sorting01:45

Regulation of Nuclear Protein Sorting

Nuclear protein sorting regulates nucleus composition and gene expression, crucial for determining the fate of a eukaryotic cell. Hence, the entry and exit of molecules across the nuclear envelope is a tightly controlled process. Nuclear protein sorting can be inhibited by one of the following ways: 1) masking cargo signal sequences, 2) modifying the nuclear receptor's affinity for cargo, 3) controlling the nuclear pore size, 4) retaining the cargo during its transit to the cytosol or the...
Nonsense-mediated mRNA Decay02:27

Nonsense-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,...