Related Experiment Video

Updated: Apr 21, 2026

Nonradioactive Assay to Measure Polynucleotide Phosphorylation of Small Nucleotide Substrates
06:49

Nonradioactive Assay to Measure Polynucleotide Phosphorylation of Small Nucleotide Substrates

Published on: May 8, 2020

4.4K

Phosphorylation status of human RNA-binding protein 8A in cells and its inhibitory regulation by Magoh

Yasuhito Ishigaki1, Yuka Nakamura2, Takanori Tatsuno2

  • 1Medical Research Institute, Kanazawa Medical University, Uchinada, Kahoku, Ishikawa 920-0293, Japan ishigaki@kanazawa-med.ac.jp.

Experimental Biology and Medicine (Maywood, N.J.)
|October 29, 2014
PubMed

Insights

RNA-binding protein 8A (RBM8A) is highly phosphorylated in human cells, occurring before its association with Magoh. This phosphorylation is crucial for mRNA metabolism and nonsense-mediated decay (NMD).

Area of Science:

  • Molecular Biology
  • RNA Metabolism
  • Protein Phosphorylation

Background:

  • The exon junction complex (EJC) is vital for mRNA processing, with RNA-binding protein 8A (RBM8A) and Magoh (Mago-nashi homolog, proliferation-associated) being key components.
  • RBM8A's role in nonsense-mediated mRNA decay (NMD) is established, but its phosphorylation status and regulatory mechanisms remain unclear.

Purpose of the Study:

  • To comprehensively investigate the phosphorylation status and sites of RBM8A in human cells.
  • To elucidate the relationship between RBM8A phosphorylation and its interaction with Magoh.

Main Methods:

  • Utilized Phos-tag gel electrophoresis to analyze RBM8A phosphorylation in whole-cell lysates, nuclear/cytoplasmic fractions, and EJC components.
  • Employed site-directed mutagenesis to identify specific serine residues involved in RBM8A phosphorylation.
  • Performed in vitro and in vivo experiments to assess the impact of Magoh on RBM8A phosphorylation.

Main Results:

  • The majority of endogenous RBM8A is phosphorylated throughout the cell cycle, in both nuclear and cytoplasmic compartments, and within the EJC.
  • Serine residues 166 and 168 were identified as major phosphorylation sites, with S168 phosphorylation potentially preceding or inhibiting S166 phosphorylation.
  • Magoh was found to inhibit RBM8A phosphorylation both in vitro and in vivo.

Conclusions:

  • RBM8A undergoes rapid and extensive phosphorylation upon synthesis, preceding its complex formation with Magoh.
  • Phosphorylation of RBM8A is a critical regulatory step in its function within the EJC and potentially in NMD pathways.
Keywords:
MagohPhos-tag gelRBM8A(Y14)mRNAphosphorylation

More Related Videos

Studying RNA Interactors of Protein Kinase RNA-Activated during the Mammalian Cell Cycle10:05

Studying RNA Interactors of Protein Kinase RNA-Activated during the Mammalian Cell Cycle

Published on: March 5, 2019

6.1K
A High Resolution Method to Monitor Phosphorylation-dependent Activation of IRF311:44

A High Resolution Method to Monitor Phosphorylation-dependent Activation of IRF3

Published on: January 24, 2016

11.7K

Related Concept Videos

Chromatin Structure Regulates pre-mRNA Processing02:41

Chromatin Structure Regulates pre-mRNA Processing

In eukaryotic cells, nascent mRNA transcripts need to undergo many post-transcriptional modifications to reach the cell cytoplasm and translate into functional proteins. For a long time, transcription and pre-mRNA processing were considered two independent events that occur sequentially in the cell. However, it has now been well established that transcription and pre-mRNA processing are two simultaneous processes that are precisely regulated inside the cell.
The chromatin structure, especially...
6.6K
Regulation of Expression at Multiple Steps01:23

Regulation of Expression at Multiple Steps

The gene expression in cells is regulated at different stages: (i) transcription, (ii) RNA processing, (iii) RNA localization, and (iv) translation. Transcriptional regulation is mediated by regulatory proteins such as transcription factors, activators, or repressors—these control gene expression by initiating or inhibiting the transcription of genes. Once a precursor or pre-mRNA is produced, it undergoes post-transcriptional modification, including 5' capping, splicing, and the...
1.3K
RNA Polymerase II Accessory Proteins02:36

RNA Polymerase II Accessory Proteins

Proteins that regulate transcription can do so either via direct contact with RNA Polymerase or through indirect interactions facilitated by adaptors, mediators, histone-modifying proteins, and nucleosome remodelers. Direct interactions to activate transcription is seen in bacteria as well as in some eukaryotic genes. In these cases, upstream activation sequences are adjacent to the promoters, and the activator proteins interact directly with the transcriptional machinery. For example, in...
8.8K
Covalently Linked Protein Regulators02:04

Covalently Linked Protein Regulators

Proteins can undergo many types of post-translational modifications, often in response to changes in their environment. These modifications play an important role in the function and stability of these proteins. Covalently linked molecules include functional groups, such as methyl, acetyl, and phosphate groups, and also small proteins, such as ubiquitin. There are around 200 different types of covalent regulators that have been identified.
These groups modify specific amino acids in a protein....
8.2K
RNA Stability01:53

RNA Stability

Intact DNA strands can be found in fossils, while scientists sometimes struggle to keep RNA intact under laboratory conditions. The structural variations between RNA and DNA underlie the differences in their stability and longevity. Because DNA is double-stranded, it is inherently more stable. The single-stranded structure of RNA is less stable but also more flexible and can form weak internal bonds. Additionally, most RNAs in the cell are relatively short, while DNA can be up to 250 million...
31.3K
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...
19.9K