Dissection of the Ascaris Sperm Motility Machinery Identifies Key Proteins Involved in Major Sperm Protein-based Amoeboid Locomotion

AUTOR(ES)

Buttery, Shawnna M.

FONTE

The American Society for Cell Biology

RESUMO

Although Ascaris sperm motility closely resembles that seen in many other types of crawling cells, the lamellipodial dynamics that drive movement result from modulation of a cytoskeleton based on the major sperm protein (MSP) rather than actin. The dynamics of the Ascaris sperm cytoskeleton can be studied in a cell-free in vitro system based on the movement of plasma membrane vesicles by fibers constructed from bundles of MSP filaments. In addition to ATP, MSP, and a plasma membrane protein, reconstitution of MSP motility in this cell-free extract requires cytosolic proteins that orchestrate the site-specific assembly and bundling of MSP filaments that generates locomotion. Here, we identify a fraction of cytosol that is comprised of a small number of proteins but contains all of the soluble components required to assemble fibers. We have purified two of these proteins, designated MSP fiber proteins (MFPs) 1 and 2 and demonstrated by immunolabeling that both are located in the MSP cytoskeleton in cells and in fibers. These proteins had reciprocal effects on fiber assembly in vitro: MFP1 decreased the rate of fiber growth, whereas MFP2 increased the growth rate.

Documentos Relacionados

• Prions in Saccharomyces and Podospora spp.: Protein-Based Inheritance
• A protein-based therapeutic for human cytomegalovirus infection
• Engineering a signal transduction mechanism for protein-based biosensors
• Whey protein-based films incorporated with oregano essential oil
• A Novel Fluorescent Protein-Based Biosensor for Gram-Negative Bacteria