Related Experiment Video
Updated: May 30, 2026

Assessment of Mitochondrial Fission/Fusion Dynamics in Kidney Proximal Tubular Cells
Published on: November 14, 2025
RALA and RALBP1 regulate mitochondrial fission at mitosis
David F Kashatus1, Kian-Huat Lim, Donita C Brady
1Department of Pharmacology and Cancer Biology, Duke University Medical Center, Durham, North Carolina 27710, USA.
Mitochondrial fission during cell division relies on proteins RALA and RALBP1. These proteins, regulated by Aurora A and cyclin B-CDK1 kinases, ensure proper mitochondrial distribution and cell function.
Area of Science:
- Cell Biology
- Molecular Biology
- Mitochondrial Dynamics
Background:
- Mitochondria form dynamic networks essential for cell function.
- Mitochondrial fission is crucial for equal distribution during cell division (mitosis).
- Previous studies identified DRP1 GTPase and cyclin B-CDK1 in mitotic mitochondrial fission.
Purpose of the Study:
- To elucidate the roles of RALA and RALBP1 in mitotic mitochondrial fission.
- To identify the upstream regulators of RALA and RALBP1 in this process.
- To understand how these factors contribute to mitochondrial distribution and cell viability.
Main Methods:
- Investigated the interaction and localization of RALA, RALBP1, DRP1, Aurora A, and cyclin B-CDK1.
- Utilized genetic disruption of RALA and RALBP1.
- Assessed mitochondrial fission, segregation, ATP levels, and cell number.
Main Results:
- Aurora A phosphorylates RALA, promoting its mitochondrial localization and recruitment of RALBP1 and DRP1.
- RALBP1 links cyclin B-CDK1 activity to DRP1 phosphorylation at Ser 616.
- Disruption of RALA or RALBP1 impairs mitochondrial fission, segregation, and reduces ATP levels and cell number.
Conclusions:
- Aurora A and cyclin B-CDK1 converge on RALA and RALBP1 to control mitochondrial fission.
- This pathway is vital for proper mitochondrial distribution during cytokinesis.
- The RALA-RALBP1 pathway is essential for maintaining mitochondrial function and cell viability.
Related Concept Videos
Restarting Stalled Replication Forks
Rab Cascades
The Contractile Ring
A small GTPase, RhoA, controls the function and assembly of the contractile ring. RhoA belongs to the Ras superfamily of proteins. The activation of formins by RhoA promotes...
Ribosomal RNA Synthesis
Ribosome biogenesis begins with the synthesis of 5S and 45S pre-rRNAs by distinct RNA polymerases. The primary transcripts are extensively processed and modified before they are bound and folded by ribosomal proteins and assembly factors,...
Disassembly of Intermediate Filaments
Keratin proteins, found at the cell periphery near cell junctions, undergo a cycle of assembly and disassembly. In Type...
Distribution of Cytoplasmic Content
Distribution of cytoplasmic determinants
The cytoplasm contains various organelles, as well as salts, proteins, and water. The distribution of small...

