| Autor: |
Liu, Feizhou, Ortiz, Irving, Hutagalung, Alex, Bauer, Christopher C., Cook, Richard G., Epstein1, Henry F. |
| Zdroj: |
Journal of Cell Science; November 2000, Vol. 113 Issue: 22 p4001-4012, 12p |
| Abstrakt: |
Muscle thick filaments are highly organized supramolecular assemblies of myosin and associated proteins with lengths, diameters and flexural rigidities characteristic of their source. The cores of body wall muscle thick filaments of the nematode Caenorhabditis elegans are tubular structures of paramyosin sub-filaments coupled by filagenins and have been proposed to serve as templates for the assembly of native thick filaments. We have characterized α- and γ-filagenins, two novel proteins of the cores with calculated molecular masses of 30,043 and 19,601 and isoelectric points of 10.52 and 11.49, respectively. Western blot and immunoelectron microscopy using affinity-purified antibodies confirmed that the two proteins are core components. Immunoelectron microscopy of the cores revealed that they assemble with different periodicities. Immunofluorescence microscopy showed that α-filagenin is localized in the medial regions of the A-bands of body wall muscle cells whereas γ-filagenin is localized in the flanking regions, and that α-filagenin is expressed in 1.5-twofold embryos while γ-filagenin becomes detectable only in late vermiform embryos. The expression of both proteins continues throughout later stages of development. C. elegans body wall muscle thick filaments of these developmental stages have distinct lengths. Our results suggest that the differential assembly of α- and γ-filagenins into thick filaments of distinct lengths may be developmentally regulated. |
| Databáze: |
Supplemental Index |
| Externí odkaz: |
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