Related Experiment Video

Updated: Jul 10, 2026

Assessment of Mitochondrial Fission/Fusion Dynamics in Kidney Proximal Tubular Cells
06:14

Assessment of Mitochondrial Fission/Fusion Dynamics in Kidney Proximal Tubular Cells

Published on: November 14, 2025

Structural basis for recruitment of mitochondrial fission complexes by Fis1

Yan Zhang1, David C Chan

  • 1Division of Biology, California Institute of Technology, 1200 East California Boulevard, MC 114-96, Pasadena, CA 91125, USA.

Proceedings of the National Academy of Sciences of the United States of America
|November 14, 2007
PubMed

Insights

Researchers discovered how Fis1 protein recruits the mitochondrial fission complex using a novel binding mode. This finding clarifies mitochondrial dynamics and aids in manipulating mitochondrial fission.

Area of Science:

  • Cell Biology
  • Molecular Biology
  • Biochemistry

Background:

  • Mitochondrial fission is crucial for cell physiology and apoptosis.
  • The Fis1 protein initiates mitochondrial fission by recruiting the Dnm1 GTPase.
  • Fis1 interacts with Dnm1 through adaptors Mdv1 and Caf4.

Purpose of the Study:

  • To elucidate the structural mechanism of Fis1-adaptor interactions.
  • To understand how Fis1 recruits the mitochondrial fission machinery.

Main Methods:

  • Crystallographic analysis of adaptor-Fis1 complexes.
  • Genetic and biochemical studies.

Main Results:

  • Mdv1 and Caf4 adaptors bind Fis1 via two helices to its concave and convex surfaces.
  • This dual-surface binding mode is a novel interaction for tetratricopeptide repeat (TPR) domains.
  • Both binding interfaces are essential for Mdv1/Caf4 recruitment and mitochondrial fission in vivo.

Conclusions:

  • Fis1 utilizes a unique two-interface binding mechanism to recruit mitochondrial fission factors.
  • This structural insight explains Fis1's role in mitochondrial fission complex assembly.
  • Findings facilitate future research on modulating mitochondrial fission for therapeutic purposes.

More Related Videos

Using Scaffold Liposomes to Reconstitute Lipid-proximal Protein-protein Interactions In Vitro08:53

Using Scaffold Liposomes to Reconstitute Lipid-proximal Protein-protein Interactions In Vitro

Published on: January 11, 2017

Studying Mitochondrial Structure and Function in Drosophila Ovaries09:53

Studying Mitochondrial Structure and Function in Drosophila Ovaries

Published on: January 4, 2017

Related Concept Videos

Translocation of Proteins into the Mitochondria01:19

Translocation of Proteins into the Mitochondria

Mitochondrial precursors are translocated to the internal subcompartments via independent mechanisms involving distinct protein machineries called translocases.
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,...
Energy to Drive Translocation01:37

Energy to Drive Translocation

Mitochondrial protein import is powered by two distinct energy sources: ATP hydrolysis and electrochemical potential across the inner membrane. Newly synthesized precursors are bound by cytosolic chaperones of the Hsp70 family, which guide them to the import receptors on the mitochondrial surface. Utilizing the energy of ATP hydrolysis, Hsp70 chaperones transfer these precursors to the TOM receptors on the mitochondrial outer membrane.
Generally, polypeptides are unfolded by two distinct...
Generation of Straight or Branched Actin Filaments01:14

Generation of Straight or Branched Actin Filaments

The straight or branched structure formation of actin filaments is controlled by nucleating proteins such as the formins and Arp2/3 complex. Formin-mediated assembly results in straight filaments, whereas Arp2/3 protein complex-mediated assembly results in branched actin filaments.
Arp2/3 Complex
Arp2/3 complex is a seven-subunit complex consisting of two proteins similar to actin- Arp2 and Arp3, and five other subunits that help keep Arp2 and Arp3 inactive. When required, the complex is...
Mechanism of Filopodia Formation01:39

Mechanism of Filopodia Formation

Filopodia are thin, actin-rich cellular protrusions that play an important role in many fundamental cellular functions. They vary in their occurrence, length, and positioning in different cell types, suggesting their diverse roles.
Their main function is to guide migrating cells during normal tissue morphogenesis or cancer metastasis by recognizing and making initial contacts with the extracellular matrix. However, they can also act as stationary cell anchors or help to establish communication...
Mitochondrial Protein Sorting01:39

Mitochondrial Protein Sorting

Mitochondria are double-membrane organelles of the eukaryotes involved in cellular metabolism, signaling, ATP synthesis, and programmed cell death.  Each of these processes requires specific proteins and enzymes that must be correctly sorted to the right mitochondrial subcompartment for the proper functioning of the organelle.
Most of these mitochondrial proteins are encoded by the nucleus and imported to the mitochondria as unfolded or loosely folded precursors. Mitochondrial precursors...
Porin Insertion in the Outer Mitochondrial Membrane01:12

Porin Insertion in the Outer Mitochondrial Membrane

Porins are beta-barrel proteins translocated to the mitochondrial outer membrane through the TOM complex into the intermembrane space. Porin precursors bind TIM chaperones within the intermembrane space and are guided to the Sorting and Assembly Machinery complex or SAM complex on the outer mitochondrial membrane.
Three models describe the assembly of porins by the SAM complex and their insertion into the outer membrane. Model 1 suggests that porins are assembled outside the SAM channel as the...