Related Experiment Video
Updated: Oct 5, 2025

Imaging the Intracellular Trafficking of APP with Photoactivatable GFP
Published on: October 17, 2015
Endoplasmic reticulum-translocation is essential for APOL1 cellular toxicity
Etty Kruzel-Davila1,2, Ira Bavli-Kertselli1, Ayala Ofir1
1Department of Nephrology, Rambam Health Care Campus, Haifa, Israel.
Blocking APOL1 toxicity may prevent chronic kidney disease (CKD). Deleting specific amino acids or targeting ER translocation shows promise in mitigating APOL1-associated kidney damage in at-risk populations.
Area of Science:
- Genetics and Molecular Biology
- Nephrology
- Cellular Biology
Background:
- Two variants of the apolipoprotein L1 (APOL1) gene are responsible for over 70% of increased chronic kidney disease (CKD) risk in individuals of African ancestry.
- The precise mechanism initiating cell injury by APOL1 risk variants is not fully understood.
Purpose of the Study:
- To investigate upstream therapeutic strategies for blocking APOL1 toxicity.
- To explore the role of ER translocation and trafficking in APOL1-mediated cytotoxicity.
Main Methods:
- Deletion of the first six amino acids of exon 4 in the APOL1 gene.
- Assessing APOL1 cytotoxicity in yeast and fly models with altered ER translocon protein dosage.
- Utilizing an inhibitor of ER to Golgi trafficking.
Main Results:
- Deletion of the N-terminal six amino acids of exon 4 abrogated APOL1 cytotoxicity by preventing ER lumen translocation and signal peptide splicing.
- Reduced dosage of ER translocon genes partially abrogated APOL1 lethality in yeast and flies.
- Inhibition of ER to Golgi trafficking also reduced APOL1-associated lethality.
Conclusions:
- Targeting the MSALFL sequence or promoting exon 4 skipping are potential therapeutic strategies.
- Interfering with APOL1 translocation to the ER lumen or ER-Golgi trafficking may mitigate APOL1-associated CKD risk.
Related Concept Videos
Export of Misfolded Proteins out of the ER
Post-translational Translocation of Proteins to the RER
Targeting proteins to the ER
Hsp40 and Hsp70 chaperone molecules bind the translated proteins in the cytosol to prevent their folding. The chaperone binding helps to keep the signal...
The Unfolded Protein Response
Cotranslational Protein Translocation
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...
Protein Translocation Machinery on 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...
Translocation of Proteins into the Mitochondria
Sorting of outer membrane proteins:
Mitochondrial outer membrane proteins are of two types: the transmembrane, beta-barrel porins, and the membrane-anchored, alpha-helical proteins. Beta-barrel porin precursors are translocated by the TOM complex and inserted into the outer mitochondrial membrane by the SAM complex. In contrast,...

