Related Experiment Video

Updated: Jan 21, 2026

Evaluating the Function of the Foot Core System in the Elderly
08:25

Evaluating the Function of the Foot Core System in the Elderly

Published on: March 11, 2022

3.2K

The multi PAM2 protein Upa2 functions as novel core component of endosomal mRNA transport

Silke Jankowski1, Thomas Pohlmann1, Sebastian Baumann1

  • 1Institute for Microbiology, Cluster of Excellence on Plant Sciences, Heinrich Heine University Düsseldorf, Düsseldorf, Germany.

EMBO Reports
|July 25, 2019
PubMed

Insights

Researchers identified Upa2, a novel protein essential for mRNA transport in fungal hyphae. This protein acts as a scaffold, ensuring proper protein expression by facilitating the movement of messenger RNA (mRNA) and associated proteins.

Area of Science:

  • Molecular Biology
  • Cell Biology
  • Mycology

Background:

  • Spatiotemporal protein expression is regulated by mRNA transport.
  • mRNA transport occurs via ribonucleoprotein complexes.
  • Endosomal mRNA transport in fungal hyphae is a well-studied mechanism with known components, but gaps remain.

Purpose of the Study:

  • To identify novel core components of endosomal mRNA transport in fungal hyphae.
  • To characterize the function and localization of the newly identified protein, Upa2.

Main Methods:

  • Protein identification and characterization.
  • Analysis of Upa2's role in mRNA and protein Pab1 transport.
  • Localization studies of Upa2 on endosomes.
  • Functional assays during hyphal growth.

Main Results:

  • A novel 232 kDa protein, Upa2, containing multiple PAM2 motifs was identified as a core component.
  • Loss of Upa2 disrupts the transport of cargo mRNAs and Pab1.
  • Upa2 localizes to transport endosomes in an mRNA-dependent manner.
  • PAM2 motifs are dispensable for Upa2 function; an N-terminal effector domain and C-terminal GWW motif are crucial for function and localization, respectively.

Conclusions:

  • Upa2 is a novel core component of endosomal mRNA transport in fungal hyphae.
  • Upa2 plays a crucial scaffolding role in this process.
  • Specific domains of Upa2 mediate its function and localization, independent of its PAM2 motifs.
Keywords:
MLLE domainPAM2 motifendosomemicrotubulepoly(A)-binding protein

More Related Videos

In Vitro Polymerization of F-actin on Early Endosomes12:15

In Vitro Polymerization of F-actin on Early Endosomes

Published on: August 28, 2017

9.6K
Major Components of the Light Microscope08:08

Major Components of the Light Microscope

Published on: July 30, 2008

24.4K

Related Concept Videos

Regulated mRNA Transport02:22

Regulated mRNA Transport

In eukaryotes, transcription and translation are compartmentalized; an mRNA is first synthesized in the nucleus and then selectively transported to the cytoplasm for protein synthesis. Before transport, a pre-mRNA undergoes several steps of post-transcriptional modifications including splicing, 5' capping, and the addition of a poly-adenine tail. Various proteins bind to the pre-mRNA during these modifications. The mRNA transport takes place with the help of multiple proteins playing...
6.9K
Regulated mRNA Transport02:22

Regulated mRNA Transport

3.3K
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...
8.7K
Electron Transport Chain Components01:29

Electron Transport Chain Components

The electron transport chain (ETC) is a crucial metabolic pathway that facilitates energy conversion in prokaryotic and eukaryotic cells. In eukaryotes, the ETC comprises four membrane-associated protein complexes in the inner mitochondrial membrane. In prokaryotes, the ETC in the plasma membrane can vary in composition, with fewer or different complexes depending on the organism and environmental conditions. These complexes transfer electrons from electron donors, such as NADH and FADH2, to...
921
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,...
11.7K
pre-mRNA Processing02:01

pre-mRNA Processing

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...
57.2K