minus-end directed microfilament motor activity

Definition

Target type: molecularfunction

A motor activity that generates movement along a microfilament towards the minus end, driven by ATP hydrolysis. The minus end of an actin filament is the end that does not preferentially add actin monomers. [GOC:dph, PMID:10519557]

Minus-end directed microfilament motor activity is a molecular function that describes the movement of proteins along actin filaments towards their minus end. This activity is essential for a wide range of cellular processes, including:

- **Cell migration:** Minus-end directed motors are crucial for the retrograde flow of actin filaments during cell migration, allowing cells to move and change shape.
- **Cytokinesis:** During cell division, minus-end directed motors are involved in the formation of the contractile ring, which pinches off the cell into two daughter cells.
- **Organelle transport:** These motors transport organelles, such as vesicles and mitochondria, along actin filaments, ensuring their proper distribution within the cell.
- **Signal transduction:** Minus-end directed motors can regulate signaling pathways by transporting signaling molecules along actin filaments, enabling communication within the cell.

**Mechanism of Action:**

Minus-end directed motors achieve their movement by interacting with actin filaments through specific binding sites. They utilize the energy released from ATP hydrolysis to undergo conformational changes that drive them along the filament. These motors often bind to other cellular components, such as cargo molecules or signaling proteins, facilitating their transport or regulation.

**Key Proteins:**

Several proteins exhibit minus-end directed microfilament motor activity, including:

- **Myosin VI:** A highly processive motor that is involved in endocytosis, exocytosis, and the transport of vesicles.
- **Myosin VIIa:** A motor protein essential for hearing and balance, it is involved in the proper assembly and function of hair cells in the inner ear.
- **Myosin XVa:** Plays a role in stereocilia formation and the development of the auditory system.

**Dysregulation and Disease:**

Mutations in minus-end directed motors can lead to various human diseases, including:

- **Hearing loss:** Defects in Myosin VIIa and Myosin XVa can cause sensorineural hearing loss.
- **Developmental defects:** Mutations in these motors can disrupt cell migration and organ development.
- **Neurological disorders:** Dysfunction in minus-end directed motors can contribute to neurodegenerative diseases.

In summary, minus-end directed microfilament motor activity is a fundamental cellular process that powers a wide range of cellular functions, from movement and organelle transport to signaling and development.'
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Proteins (1)

Compounds (1)