JoVE - Journal of Visualized Experiments
JoVE Visualize
Contact Us

The U6 snRNA m6A Methyltransferase METTL16 Regulates SAM Synthetase Intron Retention

  • 0Department of Microbiology, UT Southwestern Medical Center, Dallas, TX 75390, USA.
Cell +

|

May 20, 2017

|

May 20, 2017

View abstract on PubMed

Summary

This summary is machine-generated.

The methyltransferase METTL16 regulates SAM synthetase (MAT2A) expression by controlling alternative splicing. This mechanism helps maintain cellular S-adenosylmethionine (SAM) homeostasis, with METTL16 also methylating U6 snRNA.

Area Of Science

  • Molecular Biology
  • Gene Regulation
  • RNA Biology

Background

  • S-adenosylmethionine (SAM) is crucial for numerous biological processes.
  • METTL16 is an N6-adenosine methyltransferase with known roles.
  • The regulation of SAM synthetase (MAT2A) expression is vital for cellular SAM levels.

Purpose Of The Study

  • To investigate the role of METTL16 in regulating MAT2A expression.
  • To elucidate the mechanism by which SAM levels influence MAT2A expression.
  • To identify the function of METTL16 in U6 spliceosomal small nuclear RNA (snRNA) modification.

Main Methods

  • Analysis of gene expression and splicing.
  • RNA immunoprecipitation (RIP) assays to determine protein-RNA interactions.
  • In vitro methylation assays.
  • Cellular SAM level measurements.

Main Results

  • METTL16 regulates human MAT2A expression via alternative splicing of a retained intron.
  • SAM depletion induces MAT2A expression through METTL16-dependent splicing of a hairpin structure in the MAT2A 3' UTR.
  • METTL16 is identified as the methyltransferase for U6 snRNA.
  • Increased METTL16 occupancy on the MAT2A 3' UTR promotes splicing.

Conclusions

  • METTL16 plays a dual role in regulating SAM homeostasis and U6 snRNA modification.
  • The N6-adenosine methyltransferase METTL16 has evolved a vertebrate-specific function in SAM regulation.
  • METTL16-mediated splicing of MAT2A is a key mechanism for maintaining cellular SAM levels under stress.

Keywords:

Related Concept Videos

RNA Splicing 01:32

61.0K

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...

RNA Stability 01:53

35.9K

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...

Chromatin Structure Regulates pre-mRNA Processing 02:41

8.3K

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...

Alternative RNA Splicing 02:18

25.4K

Alternative RNA splicing is the regulated splicing of exons and introns to produce different mature mRNAs from a single pre-mRNA. Unlike in constitutive splicing where a single gene produces a single type of mRNA, alternative splicing allows an organism to produce multiple proteins from a single gene and plays an important role in protein diversity.
There are five types of alternative RNA splicing that vary in the ways the pre-mRNA segments are removed or retained in the mature mRNA. The first...

pre-mRNA Processing 02:01

57.8K

In eukaryotic cells, transcripts made by RNA polymerase are modified and processed before exiting the nucleus. Unprocessed RNA is called precursor mRNA or pre-mRNA to distinguish it from mature mRNA.
Once about 20-40 ribonucleotides have been joined together by RNA polymerase, a group of enzymes adds a “cap” to the 5’ end of the growing transcript. In this process, a 5’ phosphate is replaced by modified guanosine that has a methyl group attached to it (7-Methyl...

Pre-mRNA Processing: Modification of pre-mRNA Ends 01:35

16.1K

In eukaryotic cells, transcripts made by RNA polymerase are modified and processed before exiting the nucleus. Unprocessed RNA is called precursor mRNA or pre-mRNA to distinguish it from mature mRNA.
Once about 20-40 ribonucleotides have been joined together by RNA polymerase, a group of enzymes adds a cap to the 5' end of the growing transcript. In this process, a 5' phosphate is replaced by modified guanosine that has a methyl group attached (7-methyl guanosine). This 5' cap helps...