Protein 4.1 and its interaction with other cytoskeletal proteins in Xenopus laevis oogenesis
| Autor: | Brian Dale, Rosa Carotenuto, Nadia De Marco, Isabel Correas, Maria Carmela Vaccaro, Tamara C. Petrucci, Martin Wilding |
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| Přispěvatelé: | Carotenuto, Rosa, T. C., Petrucci, I., Correa, M. C., Vaccaro, DE MARCO, Nadia, B., Dale, M., Wilding |
| Jazyk: | English, Middle (1100-1500) |
| Rok vydání: | 2009 |
| Předmět: |
Cytoplasm
Histology Immunoprecipitation Blotting Western Xenopus macromolecular substances Mitochondrial cloud Biology Xenopus Proteins Pathology and Forensic Medicine Cytokeratin Oogenesis Animals Protein Isoforms Spectrin Cytoskeleton Germinal vesicle Microscopy Confocal Cell Biology General Medicine biology.organism_classification Actins Cell biology Microscopy Fluorescence Keratins xenopus laevis oogenesi protein 4.1 Protein Binding |
| Popis: | In human red blood cells, protein 4.1 (4.1R) is an 80-kDa polypeptide that stabilizes the spectrin–actin network and anchors it to the plasma membrane. In non-erythroid cells there is a great variety of 4.1R isoforms, mainly generated by alternative pre-mRNA splicing, which localize at various intracellular sites, including the nucleus. We studied protein 4.1R distribution in relation to β-spectrin, actin and cytokeratin during Xenopus oogenesis. Immunoprecipitation experiments indicate that at least two isoforms of protein 4.1R are present in Xenopus laevis oocytes: a 56-kDa form in the cytoplasm and a 37-kDa form in the germinal vesicle (GV). Antibodies to β-spectrin reveal two bands of 239 and 100 kDa in the cytoplasm. Coimmunoprecipitation experiments indicate that both the 37- and 56-kDa isoforms of protein 4.1R associate with the 100-kDa isoform of β-spectrin. Moreover, the 56-kDa form coimmunoprecipitates with a cytokeratin of the same molecular weight. Confocal immunolocalization shows that protein 4.1R distribution is in the peripheral cytoplasm, in the mitochondrial cloud (MC) and in the GV of previtellogenic oocytes. In the cytoplasm of vitellogenic oocytes, a loose network of fibers stained by the anti-protein 4.1R antibody spreads across the cytoplasm. β-Spectrin has a similar distribution. Protein 4.1R was found to colocalize with actin in the cortex of oocytes in the form of fluorescent dots. Double immunolocalization of protein 4.1R and cytokeratin depicts two separate networks that overlap throughout the whole cytoplasm. Protein 4.1R filaments partially colocalize with cytokeratin in both the animal and vegetal hemispheres. We hypothesize that protein 4.1R could function as a linker protein between cytokeratin and the actin-based cytoskeleton. |
| Databáze: | OpenAIRE |
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