Related Experiment Video
Updated: Jun 1, 2026
06:27
Isolation and Characterization of Exosomes from Skeletal Muscle Fibroblasts
Published on: May 16, 2020
Functions of the cytoplasmic exosome
Daneen Schaeffer1, Amanda Clark, A Alejandra Klauer
1Department of Microbiology and Molecular Genetics, University of Texas Health Science Center-Houston, Houston, Texas, USA.
Advances in Experimental Medicine and Biology
|May 31, 2011
Summary
The cytoplasmic exosome, a protein complex, degrades cellular messenger RNAs (mRNAs) and participates in mRNA surveillance. Specific cofactors are essential for its cytoplasmic functions, directing it to RNA targets.
Area of Science:
- Molecular Biology
- Cell Biology
- RNA Biology
Background:
- The exosome is a protein complex found in eukaryotic cells, crucial for RNA processing and degradation.
- Its core includes essential proteins like ribonuclease Rrp44p and functions in both cytoplasm and nucleus.
- The cytoplasmic exosome's role in mRNA turnover and surveillance is conserved across species, notably studied in Saccharomyces cerevisiae.
Purpose of the Study:
- To review the cofactors and functions of the cytoplasmic exosome.
- To highlight unanswered questions regarding the mechanisms of cytoplasmic exosome function.
Main Methods:
- Literature review of existing studies on cytoplasmic exosome cofactors and functions.
- Comparative analysis of exosome function in yeast and metazoans.
Main Results:
- The cytoplasmic exosome utilizes a distinct set of four proteins not involved in nuclear functions.
- These cofactors are presumed to target the exosome to specific cytoplasmic RNA substrates.
- Functional aspects of the cytoplasmic exosome are largely conserved between yeast and metazoan cells.
Conclusions:
- The cytoplasmic exosome plays a vital role in cellular mRNA metabolism and quality control.
- Understanding the specific roles of cofactors is key to elucidating cytoplasmic exosome mechanisms.
- Further research is needed to address outstanding questions on how the cytoplasmic exosome is directed to its targets.
Related Concept Videos
01:36Overview of Exosomes
Exosomes are stable, lipid bilayer-enclosed vesicles capable of crossing biological barriers. They can carry a wide range of molecules required for intercellular communication. Once exosomes are released from the cell where they originated, they enter a recipient cell through various pathways such as fusion, receptor-mediated endocytosis, macropinocytosis, and phagocytosis.
Stahl et al. discovered exosomes in 1983, but the exosomes were initially considered waste products released from the...
Stahl et al. discovered exosomes in 1983, but the exosomes were initially considered waste products released from the...
00:50Exocytosis
Exocytosis is a process that releases molecules outside the cell. Like other bulk transport mechanisms, exocytosis requires energy.
Exocytosis is the opposite of endocytosis, which brings molecules inside the cell. Sometimes, the released materials are signaling molecules. For example, neurons typically use exocytosis to release neurotransmitters. Cells also use exocytosis to insert proteins such as ion channels into their cell membranes, secrete proteins for use in the extracellular matrix, or...
Exocytosis is the opposite of endocytosis, which brings molecules inside the cell. Sometimes, the released materials are signaling molecules. For example, neurons typically use exocytosis to release neurotransmitters. Cells also use exocytosis to insert proteins such as ion channels into their cell membranes, secrete proteins for use in the extracellular matrix, or...
00:51Exocytosis
Exocytosis is used to release material from cells. Like other bulk transport mechanisms, exocytosis requires energy.
01:18Vesicular Trasport: Endocytosis, Transcytosis and Exocytosis
Vesicular transport is a cellular process that encompasses the engulfment of particles or dissolved substances by cells. It involves endocytosis, transcytosis, and exocytosis.
Endocytosis is a cellular mechanism that involves the inward folding of the cell membrane to create vesicles that capture and transport large drug molecules. This process comprises two distinct methods: pinocytosis (often referred to as "cell drinking") and phagocytosis (often referred to as "cell eating"). Pinocytosis is...
Endocytosis is a cellular mechanism that involves the inward folding of the cell membrane to create vesicles that capture and transport large drug molecules. This process comprises two distinct methods: pinocytosis (often referred to as "cell drinking") and phagocytosis (often referred to as "cell eating"). Pinocytosis is...
01:37Eukaryotic Compartmentalization
One of the distinguishing features of eukaryotic cells is that they contain membrane-bound organelles, such as the nucleus and mitochondria, that carry out specialized functions. Since biological membranes are only selectively permeable to solutes, they help create a compartment with controlled conditions inside an organelle. These microenvironments are tailored to the organelle's specific functions and help isolate them from the surrounding cytosol.
For example, lysosomes in the animal cells...
For example, lysosomes in the animal cells...
01:46Eukaryotic Compartmentalizations
One of the distinguishing features of eukaryotic cells is that they contain membrane-bound organelles, such as the nucleus and mitochondria, that carry out specialized functions. Since biological membranes are only selectively permeable to solutes, they help create a compartment with controlled conditions inside an organelle. These microenvironments are tailored to the organelle's specific functions and help isolate them from the surrounding cytosol.
For example, lysosomes in the animal cells...
For example, lysosomes in the animal cells...