Related Experiment Video
Updated: May 24, 2026
07:47
Directly Measuring Forces Within Reconstituted Active Microtubule Bundles
Published on: May 10, 2022
Kif2C minimal functional domain has unusual nucleotide binding properties that are adapted to microtubule
Weiyi Wang1, Qiyang Jiang, Manuela Argentini
1Institute of Protein Research, Tongji University, Shanghai 200092, China.
The Journal of Biological Chemistry
|March 10, 2012
Summary
Kinesin-13 Kif2C depolymerizes microtubules via ATP hydrolysis. Its N-terminal Neck extension confers tubulin binding specificity, stabilizing curved tubulin for disassembly.
Area of Science:
- Cell Biology
- Molecular Motors
- Cytoskeleton Dynamics
Background:
- Microtubules are dynamic polymers essential for cell structure and division.
- Kinesin motors play crucial roles in intracellular transport and microtubule dynamics.
- Kinesin-13 family members, like Kif2C, are unique in their ability to depolymerize microtubules.
Purpose of the Study:
- To elucidate the mechanism by which Kif2C depolymerizes microtubules.
- To identify the structural elements of Kif2C responsible for its depolymerase activity.
- To understand the initial binding interactions of Kif2C with tubulin.
Main Methods:
- Biochemical assays using a Kif2C monomeric construct (Kif2C-(sN+M)).
- Analysis of nucleotide-bound states and tubulin binding affinities.
- Utilizing an ATPase-deficient Kif2C mutant to study hydrolysis requirements.
- Comparative analysis with a Kif2C-Motor construct.
Main Results:
- Kif2C-(sN+M) exhibits robust microtubule depolymerase activity.
- ATP-bound Kif2C-(sN+M) preferentially binds soluble tubulin over microtubules.
- ATP hydrolysis is required for tubulin release during depolymerization.
- The N-terminal Neck extension is critical for Kif2C's tubulin binding specificity and depolymerase function.
Conclusions:
- Kif2C initiates microtubule disassembly by binding curved tubulin in an ATP-bound state.
- ATP hydrolysis precedes and drives tubulin release.
- The N-terminal Neck extension dictates Kif2C's specificity for curved tubulin and its depolymerase activity.
Related Concept Videos
01:45Destabilization of Microtubules
The destabilization of microtubules can occur during different stages of the microtubule lifecycle, such as nucleation or elongation. It can take place at either end of the microtubule or in the microtubule lattices as a whole. The lifespan of individual microtubules within a cell varies according to the cell type and stage of the cell cycle. During interphase, the lifespan of the microtubule is about 30 minutes, while during cell division, it is about 15 minutes. In axonal microtubules of...
01:18Microtubules
Microtubules are the thickest cytoskeletal filaments with a diameter of 25 nm. In prokaryotic organisms, microtubules are commonly found in locomotory appendages like cilia and flagella. In eukaryotic cells, microtubules form specialized extensions for moving fluid over the surface, like those found in cells lining the intestine.
Microtubules have two structurally similar globular protein subunits: α and β tubulins. In the cytosol, the α and β tubulins form a heterodimer. These αβ-heterodimers...
Microtubules have two structurally similar globular protein subunits: α and β tubulins. In the cytosol, the α and β tubulins form a heterodimer. These αβ-heterodimers...
01:35Microtubules
There are three types of cytoskeletal structures in eukaryotic cells—microfilaments, intermediate filaments, and microtubules. With a diameter of about 25 nm, microtubules are the thickest of these fibers. Microtubules carry out a variety of functions that include cell structure and support, transport of organelles, cell motility (movement), and the separation of chromosomes during cell division.
01:18Assembly of Cytoskeletal Filaments
Cytoskeletal filaments are polymeric forms of smaller protein subunits. However, individual cytoskeletal filaments may easily disassemble or associate with other similar filaments to form rigid structures. Microfilaments, made of actin monomers, rely on actin-binding proteins to form bundles and create networks of individual actin filaments. Microtubules rely on microtubule-associated proteins (MAPs) to form sturdy cylindrical structures. However, the proteins involved in forming complex...
01:12Adaptability of Cytoskeletal Filaments
The cytoskeleton is a complex dynamic structure performing varied functions based on cellular requirements. The adaptability of the individual filaments in the cytoskeleton determines their ability to perform various functions within the cell. It can undergo rapid reorganization during processes like cell division or remain stable for several hours as in the interphase. The adaptability of these filaments depends on stringent regulatory mechanisms. The microfilament and microtubules of the...
02:17Microtubule Instability
Microtubules are hollow cylindrical filaments having a diameter of approximately 25 nm and a length that varies from 200 nm to 25 μm. GTP-bound tubulin subunits form αβ-heterodimers for microtubule assembly. These core building blocks interact longitudinally, polymerizing into protofilaments. The protofilaments then interact with one another through lateral bonding forces to form stable cylindrical microtubules. These cylindrical filaments are dynamic as they undergo repeated assembly and...