Amoeboid Motility Without Actin: Insights into the Molecular Mechanism of Locomotion Using the Major Sperm Protein (MSP) of Nematodes

Stewart, Murray; Roberts, T.M.; Italiano, Joseph E.; King, Keith A.; Hammel, R.; Parathasathy, G.; Bullock, T.L.; McCoy, Airlie J.; Kent, Helen M.; Haaf, A.; Neuhaus, David

doi:10.2307/1543107

Cited by 2 publications

(2 citation statements)

References 6 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Indeed, a non-glycosylated state was shown for C. elegans MSP (Burke and Ward 1983;Ward 1987). The same applies to potential MSP phosphorylation, which is predicted at four sites in D. viviparus but found to be absent in C. elegans MSP (Burke and Ward 1983;Ward 1987;Stewart et al 1998). However, MSP might be phosphorylated transiently, like speculated by Haaf et al (1998) in the case of MSP activation which is necessary for filament nucleation and elongation.…”

Section: Discussionmentioning

confidence: 61%

Molecular characterization and real-time PCR transcriptional analysis of Dictyocaulus viviparus major sperm proteins

2008

View full text Add to dashboard Cite

Major sperm proteins (MSPs) represent a protein family occurring in nematodes only. Identification of the 3' and 5' untranslated region (UTR) completed the so far partial msp complementary DNA sequences of the bovine lungworm Dictyocaulus viviparus. The full-length transcript contains sequence tracts consistent with the Kozak and polyadenylation consensus sequence. On genomic level, three full-length sequences differing in three nucleotides were determined containing a 65-bp phase zero intron. Conceptual translation inferred two MSP isoforms due to one substitution within the 126-amino acid polypeptide. Bioinformatic analysis predicted that bovine lungworm MSP folds into an immunoglobulin-like seven-stranded beta sandwich as known for Caenorhabditis elegans and Ascaris suum. Furthermore, bovine lungworm MSP is confidentially predicted to be N-terminal-acetylated and secreted via a non-classical pathway. Quantitative real-time polymerase chain reaction analysis using ten developmental lungworm stages showed that msp is transcribed mainly in adult male parasites and in some degree in hypobiotic L5. However, marginal msp transcription was detectable in all of the investigated developmental lungworm stages.

show abstract

Section: Discussionmentioning

confidence: 61%

Molecular characterization and real-time PCR transcriptional analysis of Dictyocaulus viviparus major sperm proteins

2008

View full text Add to dashboard Cite

show abstract

“…Although nematode sperm cell crawling is qualitatively similar (Fig. 1 a), these cells do not contain actin filaments (5,6); they instead assemble filaments from a large cytoplasmic pool of major sperm protein (MSP) dimers. Paradoxically, MSP dimers possess a twofold rotational symmetry, form nonpolar filaments, and do not bind ATP (7).…”

Section: Introductionmentioning

confidence: 98%

Nematode Sperm Motility: Nonpolar Filament Polymerization Mediated by End-Tracking Motors

Dickinson

Purich

2007

Biophysical Journal

View full text Add to dashboard Cite

In nematode sperm cell motility, major sperm protein (MSP) filament assembly results in dynamic membrane protrusions in a manner that closely resembles actin-based motility in other eukaryotic cells. Paradoxically, whereas actin-based motility is driven by addition of ATP-bound actin subunits onto actin filament plus-ends located at the cell membrane, MSP dimers assemble from solution into nonpolar filaments that lack a nucleotide binding site. Thus, filament polarity and on-filament ATP hydrolysis, although essential for actin-based motility, appear to be unnecessary for membrane protrusions by MSP. As a potential resolution to this paradox, we propose a model for MSP filament assembly and force generation by MSP filament end-tracking proteins. In this model, ATP hydrolysis drives affinity-modulated, processive interactions between membrane-associated proteins and elongating filament ends. However, in contrast to the "actoclampin" model for actin filament end-tracking motors, ATP activates the tracking protein (or a soluble cofactor) rather than the MSP subunits themselves (in contrast to activation of actin subunits by ATP binding). The MSP end-tracking model predicts properties that are consistent with several key observations of MSP-based motility, including persistent membrane attachment, polymerization of filament ends at the membrane with depolymerization of free-filament ends away from the membrane, as well as a saturating dependence of polymerization rate on the concentration of non-MSP soluble cytoplasmic components.

show abstract

Amoeboid Motility Without Actin: Insights into the Molecular Mechanism of Locomotion Using the Major Sperm Protein (MSP) of Nematodes

Cited by 2 publications

References 6 publications

Molecular characterization and real-time PCR transcriptional analysis of Dictyocaulus viviparus major sperm proteins

Molecular characterization and real-time PCR transcriptional analysis of Dictyocaulus viviparus major sperm proteins

Nematode Sperm Motility: Nonpolar Filament Polymerization Mediated by End-Tracking Motors

Contact Info

Product

Resources

About