The C-terminal domain controls the mobility of Crumbs 3 isoforms
Ivona Djuric1, Jan Peter Siebrasse2, Ulf Schulze1
1Internal Medicine D, Molecular Nephrology, University Hospital of Muenster, Albert-Schweitzer-Campus 1, 48149 Muenster, Germany.
Biochimica Et Biophysica Acta
|March 16, 2016
Summary
Epithelial cell polarity relies on protein distribution. This study shows Crumbs family variants Crb3A and Crb3B exhibit distinct intracellular mobilities, impacting polarity protein Pals1/Mpp5 localization.
Area of Science:
- Cell Biology
- Epithelial Biology
- Membrane Biology
Background:
- Epithelial physiology requires asymmetric membrane domain distribution.
- Polarity proteins are key to this distribution, but their mobility is poorly understood.
- Crumbs family proteins, including Crb3A and Crb3B, regulate apical membrane size and identity.
Purpose of the Study:
- To investigate the intracellular and plasma-membrane-associated mobility of Crb3A and Crb3B.
- To determine how Crb3A and Crb3B influence the mobility and localization of the binding partner Pals1/Mpp5.
- To characterize the mobility of intracellular vesicles containing Crb3A or Crb3B.
Main Methods:
- Fluorescence labeling of Crb3A and Crb3B variants.
- Fluorescence recovery after photo-bleaching (FRAP) to measure protein mobility.
- Tracking of intracellular vesicles.
Main Results:
- Crb3A and Crb3B displayed differential mobilities within epithelial cells.
- The two Crb3 variants differentially affected the mobility and localization of Pals1/Mpp5.
- Vesicles containing Crb3A were less mobile than those containing Crb3B.
Conclusions:
- Crb3A and Crb3B exhibit distinct intracellular mobility patterns.
- These mobility differences contribute to the regulation of epithelial cell polarity.
- Understanding Crb3 variant mobility is crucial for deciphering epithelial organization.
More Related Videos
12:15The C. elegans Intestine As a Model for Intercellular Lumen Morphogenesis and In Vivo Polarized Membrane Biogenesis at the Single-cell Level: Labeling by Antibody Staining, RNAi Loss-of-function Analy
Published on: October 3, 2017
14.3K
10:05In Vitro Analysis of PDZ-dependent CFTR Macromolecular Signaling Complexes
Published on: August 13, 2012
11.8K
Related Concept Videos
01:13Cytoskeletal Accessory Proteins
4.2K
The cytoskeleton is an essential cell component that plays several structural and functional roles. However, the filaments that make up the cytoskeleton cannot function independently and depend on the accessory or ancillary proteins to effectively carry out their function. Accessory proteins associate with cytoskeletal filaments and their monomers, aiding filament formation and function. They also help in the cross-communication among cytoskeletal filaments. Cytoskeletal accessory proteins are...
4.2K
01:20Cotranslational Protein Translocation
10.9K
Translocation of proteins across membranes is an ancient process that occurs even in bacteria and archaebacteria. In fact, the components of the translocation machinery are still conserved between prokaryotes and eukaryotes.
Sec61 channel partners for cotranslational translocation
During cotranslational translocation, the Sec61 channel partners with the signal recognition particle (SRP), the signal recognition particle receptor (SR), and the ribosomes to transport the nascent polypeptide chain...
Sec61 channel partners for cotranslational translocation
During cotranslational translocation, the Sec61 channel partners with the signal recognition particle (SRP), the signal recognition particle receptor (SR), and the ribosomes to transport the nascent polypeptide chain...
10.9K
01:12Clathrin Coated Vesicles
10.0K
Clathrin-coated vesicles use endocytosis to transport receptors and lysosomal hydrolases from the Golgi to the lysosome in the late secretory pathway. Clathrin-mediated endocytosis was the first described endocytic process, and Clathrin-coated vesicles remain one of the most well-studied transport vesicles. The molecular machinery that generates clathrin-coated vesicles comprises over 50 proteins that precisely coordinate vesicle formation. Cell surface receptors concentrated in indented sites...
10.0K
01:32Export of Misfolded Proteins out of the ER
5.5K
After folding, the ER assesses the quality of secretory and membrane proteins. The correctly folded proteins are cleared by the calnexin cycle for transport to their final destination, while misfolded proteins are held back in the ER lumen. The ER chaperones attempt to unfold and refold the misfolded proteins but sometimes fail to achieve the correct native conformation. Such terminally misfolded proteins are then exported to the cytosol by ER-associated degradation or ERAD pathway for...
5.5K
01:45Vesicular Tubular Clusters
3.3K
After budding out from the ER membrane, some COPII vesicles lose their coat and fuse with one another to form larger vesicles and interconnected tubules called vesicular tubular clusters or VTCs. These clusters constitute a compartment at the ER-Golgi interface known as ERGIC (Endoplasmic Reticulum Golgi Intermediate Compartment). The ERGIC is a mobile membrane-bound cargo transport system that sorts proteins secreted from ER and delivers them to the Golgi.
With the help of motor proteins such...
With the help of motor proteins such...
3.3K
01:28Protein Translocation Machinery on the ER Membrane
7.3K
The translocon complex situated on the ER membrane is the main gateway for the protein secretory pathway. It facilitates the transport of nascent peptides into the ER lumen and their insertion into the ER membrane.
Sec61 protein conducting channel
In eukaryotes, the translocon complex comprises a core heterotrimeric translocator channel called the Sec61 complex. This channel includes three transmembrane proteins, Sec61α, Sec61β, and Sec61γ, and is the largest subunit of the...
Sec61 protein conducting channel
In eukaryotes, the translocon complex comprises a core heterotrimeric translocator channel called the Sec61 complex. This channel includes three transmembrane proteins, Sec61α, Sec61β, and Sec61γ, and is the largest subunit of the...
7.3K